Choosing pseudopotentials

Several pseudopotential variants labeled by suffixes exist for many elements. When making a choice, it is necessary to balance computational cost, accuracy, and transferability.

To set up a minimal working example of your calculation, follow prepare a POTCAR.
Try to create a smaller test calculation and perform your own tests to confirm if the quantity of interest is sensitive to the choice of the pseudopotential. It might be possible to opt for a computationally cheaper POTCAR and gain performance. On the other hand, it could be necessary to opt for a computationally demanding setup to obtain correct results.
With the aspects described in the next section in mind, carefully look over the recommendations for each group in the periodic table.

Aspects to refine the choice of pseudopotentials

Aspect 1: Analyze the geometry of your structure for short bonds and the valency of the ions.

Short bonds will require harder potentials, and semicore states might have to be treated as valence for certain chemical bonding. For some elements, variants for specific valency exist; for example, the suffix _2 or _3 can be used to describe fixed divalent or trivalent Lanthanides.

Aspect 2: Consider the physical or chemical property that is the objective of your calculation.

If you are only interested in a rough structure optimization, soft potentials (_s) with minimal valency may suffice. This approach might also work for phonon calculations that rely on large supercells.

On the other hand, when optimizing a magnetic structure, it may be necessary to include semicore states in the valence (_pv and _sv).

For the computation of optical properties, it is crucial to use GW potentials.

Aspect 3: Scrutinize the requirements of the method or algorithm used in your calculation.

For any calculation involving unoccupied states significantly above the Fermi energy, the _GW variants of potentials are superior and should be used. Particularly, all kinds of calculations within many-body perturbation theory need a high number of empty bands. Therefore, when GW, BSE, etc. is performed, the GW potentials should be used throughout the workflow.

For Hartree-Fock and hybrid caluclations should not be performed with soft potentials (_s). Moreover, any calculations where you switch the exchange-correlation functional should not be performed with soft potentials (_s).

For standard DFT-ground-state calculations, using _GW or _h potentials is usually unnecessary unless, e.g., the property of interest or geometry of the structure, demands it.

Recommendations and advice

Recommended PAW potentials

The table directly below highlights recommended PAW potentials in bold.

These potentials are not ideal for calculations involving a large number of excited states as needed, e.g., for optical properties or many-body perturbation theory.

Potential name	Number of valence electrons	Valence electron configuration	ENAMX [eV]
Standard PBE potentials (potpaw.64)
H	1	1s¹	250.0
H.25	0.25	1s^0.25	250.0
H.33	0.33	1s^0.33	250.0
H.42	0.42	1s^0.42	250.0
H.5	0.5	1s^0.5	250.0
H.58	0.58	1s^0.58	250.0
H.66	0.66	1s^0.66	250.0
H.75	0.75	1s^0.75	250.0
H1.25	1.25	1s^1.25	250.0
H1.33	1.33	1s^1.33	250.0
H1.5	1.5	1s^1.5	250.0
H1.66	1.66	1s^1.66	250.0
H1.75	1.75	1s^1.75	250.0
H_AE	1	1s¹	1000.0
H_h	1	1s¹	700.0
H_s	1	1s¹	200.0
He	2	1s²	478.896
He_AE	2	1s²	2135.871
Li	1	2s¹	140.0
Li_sv	3	1s² 2s¹	499.034
Be	2	2s^1.99 2p^0.01	247.543
Be_sv	4	1s² 2s^1.99 2p^0.01	308.768
B	3	2s² 2p¹	318.614
B_h	3	2s² 2p¹	700.0
B_s	3	2s² 2p¹	269.245
C	4	2s² 2p²	400.0
C_h	4	2s² 2p²	741.689
C_s	4	2s² 2p²	273.911
N	5	2s² 2p³	400.0
N_h	5	2s² 2p³	755.582
N_s	5	2s² 2p³	279.692
O	6	2s² 2p⁴	400.0
O_h	6	2s² 2p⁴	765.519
O_s	6	2s² 2p⁴	282.853
F	7	2s² 2p⁵	400.0
F_h	7	2s² 2p⁵	772.626
F_s	7	2s² 2p⁵	289.837
Ne	8	2s² 2p⁶	343.606
Na	1	3s¹	101.968
Na_pv	7	2p⁶ 3s¹	259.561
Na_sv	9	2s² 2p⁶ 3s¹	645.64
Mg	2	3s²	200.0
Mg_pv	8	2p⁶ 3s²	403.929
Mg_sv	10	2s² 2p⁶ 3s²	495.223
Al	3	3s² 3p¹	240.3
Si	4	3s² 3p²	245.345
P	5	3s² 3p³	255.04
P_h	5	3s² 3p³	390.202
S	6	3s² 3p⁴	258.689
S_h	6	3s² 3p⁴	402.436
Cl	7	3s² 3p⁵	262.472
Cl_h	7	3s² 3p⁵	409.136
Ar	8	3s² 3p⁶	266.408
K_pv	7	3p⁶ 4s¹	116.731
K_sv	9	3s² 3p⁶ 4s¹	259.264
Ca_pv	8	3p⁶ 4s²	119.559
Ca_sv	10	3s² 3p⁶ 4s²	266.622
Sc	3	3d² 4s¹	154.763
Sc_sv	11	3s² 3p⁶ 3d² 4s¹	222.66
Ti	4	3d³ 4s¹	178.33
Ti_pv	10	3p⁶ 3d³ 4s¹	222.335
Ti_sv	12	3s² 3p⁶ 3d³ 4s¹	274.61
V	5	3d⁴ 4s¹	192.543
V_pv	11	3p⁶ 3d⁴ 4s¹	263.673
V_sv	13	3s² 3p⁶ 3d⁴ 4s¹	263.673
Cr	6	3d⁵ 4s¹	227.08
Cr_pv	12	3p⁶ 3d⁵ 4s¹	265.681
Cr_sv	14	3s² 3p⁶ 3d⁵ 4s¹	395.471
Mn	7	3d⁶ 4s¹	269.864
Mn_pv	13	3p⁶ 3d⁶ 4s¹	269.864
Mn_sv	15	3s² 3p⁶ 3d⁶ 4s¹	387.187
Fe	8	3d⁷ 4s¹	267.882
Fe_pv	14	3p⁶ 3d⁷ 4s¹	293.238
Fe_sv	16	3s² 3p⁶ 3d⁷ 4s¹	390.558
Co	9	3d⁸ 4s¹	267.968
Co_pv	15	3p⁶ 3d⁸ 4s¹	271.042
Co_sv	17	3s² 3p⁶ 3d⁸ 4s¹	390.362
Ni	10	3d⁹ 4s¹	269.532
Ni_pv	16	3p⁶ 3d⁹ 4s¹	367.986
Cu	11	3d¹⁰ 4s¹	295.446
Cu_pv	17	3p⁶ 3d¹⁰ 4s¹	368.648
Zn	12	3d¹⁰ 4s²	276.723
Ga	3	4s² 4p¹	134.678
Ga_d	13	3d¹⁰ 4s² 4p¹	282.691
Ga_h	13	3d¹⁰ 4s² 4p¹	404.601
Ge	4	4s² 4p²	173.807
Ge_d	14	3d¹⁰ 4s² 4p²	310.294
Ge_h	14	3d¹⁰ 4s² 4p²	410.425
As	5	4s² 4p³	208.702
As_d	15	3d¹⁰ 4s² 4p³	288.651
Se	6	4s² 4p⁴	211.555
Br	7	4s² 4p⁵	216.285
Kr	8	4s² 4p⁶	185.331
Rb_pv	7	4p⁶ 4d^0.001 5s^0.999	121.882
Rb_sv	9	4s² 4p⁶ 4d^0.001 5s^0.999	220.112
Sr_sv	10	4s² 4p⁶ 4d^0.001 5s^1.999	229.353
Y_sv	11	4s² 4p⁶ 4d² 5s¹	202.626
Zr_sv	12	4s² 4p⁶ 4d³ 5s¹	229.898
Nb_pv	11	4p⁶ 4d⁴ 5s¹	208.608
Nb_sv	13	4s² 4p⁶ 4d⁴ 5s¹	293.235
Mo	6	4d⁵ 5s¹	224.584
Mo_pv	12	4p⁶ 4d⁵ 5s¹	224.584
Mo_sv	14	4s² 4p⁶ 4d⁵ 5s¹	242.676
Tc	7	4d⁶ 5s¹	228.694
Tc_pv	13	4p⁶ 4d⁶ 5s¹	263.523
Tc_sv	15	4s² 4p⁶ 4d⁶ 5s¹	318.703
Ru	8	4d⁷ 5s¹	213.271
Ru_pv	14	4p⁶ 4d⁷ 5s¹	240.049
Ru_sv	16	4s² 4p⁶ 4d⁷ 5s¹	318.855
Rh	9	4d⁸ 5s¹	228.996
Rh_pv	15	4p⁶ 4d⁸ 5s¹	247.408
Pd	10	4d⁹ 5s¹	250.925
Pd_pv	16	4p⁶ 4d⁹ 5s¹	250.925
Ag	11	4d¹⁰ 5s¹	249.844
Ag_pv	17	4p⁶ 4d¹⁰ 5s¹	297.865
Cd	12	4d¹⁰ 5s²	274.336
In	3	5s² 5p¹	95.934
In_d	13	4d¹⁰ 5s² 5p¹	239.211
Sn	4	5s² 5p²	103.236
Sn_d	14	4d¹⁰ 5s² 5p²	241.083
Sb	5	5s² 5p³	172.069
Te	6	5s² 5p⁴	174.982
I	7	5s² 5p⁵	175.647
Xe	8	5s² 5p⁶	153.118
Cs_sv	9	5s² 5p⁶ 6s¹	220.318
Ba_sv	10	5s² 5p⁶ 5d^0.01 6s^1.99	187.181
La	11	4f^0.0001 5s² 5p⁶ 5d^0.9999 6s²	219.292
La_s	9	5p⁶ 5d¹ 6s²	136.53
Ce	12	4f¹ 5s² 5p⁶ 5d¹ 6s²	273.042
Ce_3	11	5s² 5p⁶ 5d¹ 6s²	176.506
Ce_h	12	4f¹ 5s² 5p⁶ 5d¹ 6s²	299.9
Pr	13	4f^2.5 5s² 5p⁶ 5d^0.5 6s²	337.25
Pr_3	11	5s² 5p⁶ 5d¹ 6s²	181.719
Pr_h	13	4f^2.5 5s² 5p⁶ 5d^0.5 6s²	400.742
Nd	14	4f^3.5 5s² 5p⁶ 5d^0.5 6s²	338.34
Nd_3	11	5s² 5p⁶ 5d¹ 6s²	182.619
Nd_h	14	4f^3.5 5s² 5p⁶ 5d^0.5 6s²	402.016
Pm	15	4f^4.5 5s² 5p⁶ 5d^0.5 6s²	340.358
Pm_3	11	5s² 5p⁶ 5d¹ 6s²	176.959
Pm_h	15	4f^4.5 5s² 5p⁶ 5d^0.5 6s²	404.406
Sm	16	4f^5.5 5s² 5p⁶ 5d^0.5 6s²	341.177
Sm_3	11	5s² 5p⁶ 5d¹ 6s²	177.087
Sm_h	16	4f^5.5 5s² 5p⁶ 5d^0.5 6s²	405.382
Eu	17	4f^6.5 5s² 5p⁶ 5d^0.5 6s²	344.705
Eu_2	8	5p⁶ 6s²	99.328
Eu_3	9	5p⁶ 5d¹ 6s²	129.057
Eu_h	17	4f^6.5 5s² 5p⁶ 5d^0.5 6s²	403.212
Gd	18	4f^7.5 5s² 5p⁶ 5d^0.5 6s²	342.859
Gd_3	9	5p⁶ 5d¹ 6s²	154.332
Gd_h	18	4f^7.5 5s² 5p⁶ 5d^0.5 6s²	407.403
Tb	19	4f^8.5 5s² 5p⁶ 5d^0.5 6s²	340.855
Tb_3	9	5p⁶ 5d¹ 6s²	155.613
Tb_h	19	4f^8.5 5s² 5p⁶ 5d^0.5 6s²	405.043
Dy	20	4f^9.5 5s² 5p⁶ 5d^0.5 6s²	341.547
Dy_3	9	5p⁶ 5d¹ 6s²	155.713
Dy_h	20	4f^9.5 5s² 5p⁶ 5d^0.5 6s²	405.886
Ho	21	4f^10.5 5s² 5p⁶ 5d^0.5 6s²	343.845
Ho_3	9	5p⁶ 5d¹ 6s²	154.137
Ho_h	21	4f^10.5 5s² 5p⁶ 5d^0.5 6s²	415.91
Er	22	4f^11.5 5s² 5p⁶ 5d^0.5 6s²	346.295
Er_2	8	5p⁶ 6s²	119.75
Er_3	9	5p⁶ 5d¹ 6s²	155.037
Er_h	22	4f^11.5 5s² 5p⁶ 5d^0.5 6s²	429.583
Tm	23	4f^12.5 5s² 5p⁶ 5d^0.5 6s²	344.206
Tm_3	9	5p⁶ 5d¹ 6s²	149.221
Tm_h	23	4f^12.5 5s² 5p⁶ 5d^0.5 6s²	419.812
Yb	24	4f^13.5 5s² 5p⁶ 5d^0.5 6s²	344.312
Yb_2	8	5p⁶ 6s²	112.578
Yb_3	9	5p⁶ 5d¹ 6s²	188.359
Yb_h	24	4f^13.5 5s² 5p⁶ 5d^0.5 6s²	409.285
Lu	25	4f¹⁴ 5s² 5p⁶ 5d¹ 6s²	255.695
Lu_3	9	5p⁶ 5d¹ 6s²	154.992
Hf	4	5d³ 6s¹	220.334
Hf_pv	10	5p⁶ 5d³ 6s¹	220.334
Hf_sv	12	5s² 5p⁶ 5d⁴	237.444
Ta	5	5d⁴ 6s¹	223.667
Ta_pv	11	5p⁶ 5d⁴ 6s¹	223.667
W	6	5d⁵ 6s¹	223.057
W_sv	14	5s² 5p⁶ 5d⁵ 6s¹	223.057
Re	7	5d⁶ 6s¹	226.216
Re_pv	13	5p⁶ 5d⁶ 6s¹	226.216
Os	8	5d⁷ 6s¹	228.022
Os_pv	14	5p⁶ 5d⁷ 6s¹	228.022
Ir	9	5d⁸ 6s¹	210.864
Pt	10	5d⁹ 6s¹	230.283
Pt_pv	16	5p⁶ 5d⁹ 6s¹	294.607
Au	11	5d¹⁰ 6s¹	229.943
Hg	12	5d¹⁰ 6s²	233.204
Tl	3	6s² 6p¹	90.14
Tl_d	13	5d¹⁰ 6s² 6p¹	237.053
Pb	4	6s² 6p²	97.973
Pb_d	14	5d¹⁰ 6s² 6p²	237.835
Bi	5	6s² 6p³	105.037
Bi_d	15	5d¹⁰ 6s² 6p³	242.839
Po	6	6s² 6p⁴	159.707
Po_d	16	5d¹⁰ 6s² 6p⁴	264.565
At	7	6s² 6p⁵	161.43
Rn	8	6s² 6p⁶	151.497
Fr_sv	9	6s² 6p⁶ 7s¹	214.54
Ra_sv	10	6s² 6p⁶ 7s²	237.367
Ac	11	6s² 6p⁶ 6d¹ 7s²	172.351
Th	12	5f¹ 6s² 6p⁶ 6d¹ 7s²	247.306
Th_s	10	5f¹ 6p⁶ 6d¹ 7s²	169.363
Pa	13	5f¹ 6s² 6p⁶ 6d² 7s²	252.193
Pa_s	11	5f¹ 6p⁶ 6d² 7s²	193.466
U	14	5f² 6s² 6p⁶ 6d² 7s²	252.502
U_s	14	5f² 6s² 6p⁶ 6d² 7s²	209.23
Np	15	5f³ 6s² 6p⁶ 6d² 7s²	254.26
Np_s	15	5f³ 6s² 6p⁶ 6d² 7s²	207.713
Pu	16	5f⁴ 6s² 6p⁶ 6d² 7s²	254.353
Pu_s	16	5f⁴ 6s² 6p⁶ 6d² 7s²	207.83
Am	17	5f⁵ 6s² 6p⁶ 6d² 7s²	255.875
Cm	18	5f⁶ 6s² 6p⁶ 6d² 7s²	257.953
Cf	20	5f⁸ 6s² 6p⁶ 6d² 7s²	414.614

The following table highlights recommended PAW potentials for calculations involving many states above the Fermi energy in bold.

These potentials are not necessarily superior (and even might be inferior) for calculations involving mostly occupied states, e.g., for structural relaxations or phonons. They are optimized for scattering properties high above the Fermi level and thus have advantages if many unoccupied states are involved, as for optical properties or many-body perturbation theory.

Potential name	Number of valence electrons	Valence electron configuration	ENAMX [eV]
GW potentials
H_GW	1	1s¹	300.0
H_GW_new	1	1s¹	536.615
H_h_GW	1	1s¹	700.0
He_GW	2	1s²	405.78
Li_AE_GW	3	1s² 2p¹	433.699
Li_GW	1	2s¹	112.104
Li_sv_GW	3	1s² 2p¹	433.699
Be_GW	2	2s^1.9999 2p^0.001	247.543
Be_sv_GW	4	1s² 2p²	537.454
B_GW	3	2s² 2p¹	318.614
B_GW_new	3	2s² 2p¹	318.614
B_h_GW	3	2s² 2p¹	731.373
C_GW	4	2s² 2p²	413.992
C_GW_new	4	2s² 2p²	433.983
C_h_GW	4	2s² 2p²	741.689
C_s_GW	4	2s² 2p²	304.843
N_GW	5	2s² 2p³	420.902
N_GW_new	5	2s² 2p³	452.633
N_h_GW	5	2s² 2p³	755.582
N_s_GW	5	2s² 2p³	312.986
O_GW	6	2s² 2p⁴	414.635
O_GW_new	6	2s² 2p⁴	466.797
O_h_GW	6	2s² 2p⁴	765.519
O_s_GW	6	2s² 2p⁴	334.664
F_GW	7	2s² 2p⁵	487.698
F_GW_new	7	2s² 2p⁵	480.281
F_h_GW	7	2s² 2p⁵	848.626
Ne_GW	8	2s² 2p⁶	432.275
Ne_s_GW	8	2s² 2p⁶	318.26
Na_sv_GW	9	2s² 2p⁶ 3p¹	372.853
Mg_GW	2	3s²	126.143
Mg_pv_GW	8	2p⁶ 3s²	403.929
Mg_sv_GW	10	2s² 2p⁶ 3d²	429.893
Al_GW	3	3s² 3p¹	240.3
Al_sv_GW	11	2s² 2p⁶ 3s² 3p¹	411.109
Si_GW	4	3s² 3p²	245.345
Si_sv_GW	12	2s² 2p⁶ 3s² 3p²	547.578
P_GW	5	3s² 3p³	255.04
S_GW	6	3s² 3p⁴	258.689
Cl_GW	7	3s² 3p⁵	262.472
Ar_GW	8	3s² 3p⁶	290.599
K_sv_GW	9	3s² 3p⁶ 3d¹	248.998
Ca_sv_GW	10	3s² 3p⁶ 3d²	281.43
Sc_sv_GW	11	3s² 3p⁶ 3d³	378.961
Ti_sv_GW	12	3s² 3p⁶ 3d⁴	383.774
V_sv_GW	13	3s² 3p⁶ 3d⁵	382.321
Cr_sv_GW	14	3s² 3p⁶ 3d⁶	384.932
Mn_GW	7	3d⁶ 4s¹	278.466
Mn_sv_GW	15	3s² 3p⁶ 3d⁷	384.627
Fe_GW	8	3d⁷ 4s¹	321.007
Fe_sv_GW	16	3s² 3p⁶ 3d⁸	387.837
Co_GW	9	3d⁸ 4s¹	323.4
Co_sv_GW	17	3s² 3p⁶ 3d⁹	387.491
Ni_GW	10	3d⁹ 4s¹	357.323
Ni_sv_GW	18	3s² 3p⁶ 3d¹⁰	389.645
Cu_GW	11	3d¹⁰ 4s¹	417.039
Cu_sv_GW	19	3s² 3p⁶ 3d¹⁰ 4s¹	467.331
Zn_GW	12	3d¹⁰ 4s²	328.191
Zn_sv_GW	20	3s² 3p⁶ 3d¹⁰ 4s²	401.665
Ga_GW	3	4s² 4p¹	134.678
Ga_d_GW	13	3d¹⁰ 4s² 4p¹	404.602
Ga_sv_GW	21	3s² 3p⁶ 3d¹⁰ 4s² 4p¹	404.602
Ge_GW	4	4s² 4p²	173.807
Ge_d_GW	14	3d¹⁰ 4s² 4p²	375.434
Ge_sv_GW	22	3s² 3p⁶ 3d¹⁰ 4s² 4p²	410.425
As_GW	5	4s² 4p³	208.702
As_sv_GW	23	3s² 3p⁶ 3d¹⁰ 4s² 4p³	415.313
Se_GW	6	4s² 4p⁴	211.555
Se_sv_GW	24	3s² 3p⁶ 3d¹⁰ 4s² 4p⁴	469.344
Br_GW	7	4s² 4p⁵	216.285
Br_sv_GW	25	3s² 3p⁶ 3d¹⁰ 4s² 4p⁵	475.692
Kr_GW	8	4s² 4p⁶	252.232
Rb_sv_GW	9	4s² 4p⁶ 4d¹	221.197
Sr_sv_GW	10	4s² 4p⁶ 4d²	224.817
Y_sv_GW	11	4s² 4p⁶ 4d³	339.758
Zr_sv_GW	12	4s² 4p⁶ 4d⁴	346.364
Nb_sv_GW	13	4s² 4p⁶ 4d⁵	353.872
Mo_sv_GW	14	4s² 4p⁶ 4d⁶	344.914
Tc_sv_GW	15	4s² 4p⁶ 4d⁷	351.044
Ru_sv_GW	16	4s² 4p⁶ 4d⁸	348.106
Rh_GW	9	4d⁸ 5s¹	247.408
Rh_sv_GW	17	4s² 4p⁶ 4d⁹	351.206
Pd_GW	10	4d⁹ 5s¹	250.925
Pd_sv_GW	18	4s² 4p⁶ 4d¹⁰	356.093
Ag_GW	11	4d¹⁰ 5s¹	249.844
Ag_sv_GW	19	4s² 4p⁶ 4d¹¹	354.43
Cd_GW	12	4d¹⁰ 5s²	254.045
Cd_sv_GW	20	4s² 4p⁶ 4d¹⁰ 5s²	361.806
In_d_GW	13	4d¹⁰ 5s² 5p¹	278.624
In_sv_GW	21	4s² 4p⁶ 4d¹⁰ 5s² 5p¹	366.771
Sn_d_GW	14	4d¹⁰ 5s² 5p²	260.066
Sn_sv_GW	22	4s² 4p⁶ 4d¹⁰ 5s² 5p²	368.778
Sb_GW	5	5s² 5p³	172.069
Sb_d_GW	15	4d¹⁰ 5s² 5p³	263.1
Sb_sv_GW	23	4s² 4p⁶ 4d¹⁰ 5s² 5p³	372.491
Te_GW	6	5s² 5p⁴	174.982
Te_sv_GW	24	4s² 4p⁶ 4d¹⁰ 5s² 5p⁴	376.618
I_GW	7	5s² 5p⁵	175.647
I_sv_GW	25	4s² 4p⁶ 4d¹⁰ 5s² 5p⁵	381.674
Xe_GW	8	5s² 5p⁶	179.547
Xe_sv_GW	26	4s² 4p⁶ 4d¹⁰ 5s² 5p⁶	400.476
Cs_sv_GW	9	5s² 5p⁶ 5d¹	198.101
Ba_sv_GW	10	5s² 5p⁶ 5d¹ 6s¹	267.02
La_GW	11	4f^0.2 5s² 5p⁶ 5d^0.8 6s²	313.688
Ce_GW	12	4f¹ 5s² 5p⁶ 5d¹ 6s²	304.625
Hf_sv_GW	12	5s² 5p⁶ 5d⁴	309.037
Ta_sv_GW	13	5s² 5p⁶ 5d⁵	286.008
W_sv_GW	14	5s² 5p⁶ 5d⁶	317.132
Re_sv_GW	15	5s² 5p⁶ 5d⁷	317.012
Os_sv_GW	16	5s² 5p⁶ 5d⁸	319.773
Ir_sv_GW	17	5s² 5p⁶ 5d⁹	319.843
Pt_GW	10	5d⁹ 6s¹	248.716
Pt_sv_GW	18	5s² 5p⁶ 5d¹⁰	323.669
Au_GW	11	5d¹⁰ 6s¹	248.344
Au_sv_GW	19	5s² 5p⁶ 5d¹¹	306.658
Hg_sv_GW	20	5s² 5p⁶ 5d¹⁰ 6s²	312.028
Tl_d_GW	15	5s² 5d¹⁰ 6s² 6p¹	237.053
Tl_sv_GW	21	5s² 5p⁶ 5d¹⁰ 6s² 6p¹	316.583
Pb_d_GW	16	5s² 5d¹⁰ 6s² 6p²	237.809
Pb_sv_GW	22	5s² 5p⁶ 5d¹⁰ 6s² 6p²	317.193
Bi_GW	5	6s² 6p³	146.53
Bi_d_GW	17	5s² 5d¹⁰ 6s² 6p³	261.876
Bi_sv_GW	23	5s² 5p⁶ 5d¹⁰ 6s² 6p³	323.513
Po_d_GW	18	5s² 5d¹⁰ 6s² 6p⁴	267.847
Po_sv_GW	24	5s² 5p⁶ 5d¹⁰ 6s² 6p⁴	326.618
At_d_GW	17	5d¹⁰ 6s² 6p⁵	266.251
At_sv_GW	25	5s² 5p⁶ 5d¹⁰ 6s² 6p⁵	328.529
Rn_d_GW	18	5d¹⁰ 6s² 6p⁶	267.347
Rn_sv_GW	26	5s² 5p⁶ 5d¹⁰ 6s² 6p⁶	329.758

Selecting a pseudopotential set

Generally, we recommend using the latest release of pseudopotentials.

Tip: For compatibility reasons or to accurately reproduce another calculation, you might need to use another (older) pseudopotential release. Consult the list of available pseudopotentials.

Hydrogen-like atoms with fractional valence

Twelve hydrogen-like potentials are supplied for a valency between 0.25 and 1.75. Further potentials might become available, c.f. available pseudopotentials. These are useful, e.g., to passivate dangling surface bonds.

Mind: The POTCAR files restrict the number of digits for the valency (typically 2, at most 3 digits). Therefor, using three H.33 potentials does yield 0.99 electrons and not 1.00 electron. This can cause undesirable hole- or electron-like states. Set the NELECT tag in the INCAR file to correct the total number of electrons.

First-row elements

For the 1st row elements B, C, N, O, and F, three potential versions exist, the plain one, a hard version, and a soft version. For most purposes, the standard version of PAW potentials is most appropriate. They yield reliable results for energy cutoffs between 325 and 400 eV, where 370-400 eV are required to predict vibrational properties accurately. Binding geometries and energy differences are already well reproduced at 325 eV. The typical bond-length errors for first row dimers (N₂, CO, O₂) are about 1% compared to more accurate DFT calculations. The hard pseudopotentials _h give results that are essentially identical to the best DFT calculations presently available (FLAPW, or Gaussian with very large basis sets). The soft potentials are optimized to work around 250-280 eV. They yield reliable description for most oxides, such as V_xO_y, TiO₂, CeO₂, but fail to describe some structural details in zeolites, i.e., cell parameters, and volume.

For Hartree-Fock (HF) and hybrid-functional calculations, we strictly recommend using the standard, standard GW, or hard potentials. For instance, the O_s potential can cause unacceptably large errors even in transition metal oxides. Generally, the soft potentials are less transferable from one exchange-correlation functional to another and often fail when the exact exchange needs to be calculated.

Tip: If dimers with short bonds are present in the system (H₂O, O₂, CO, N₂, F₂, P₂, S₂, Cl₂), we recommend using the _h potentials. Specifically, C_h, O_h, N_h, F_h, P_h, S_h, Cl_h, or their _GW counterparts. Otherwise, the standard version is often the best choice for first-row elements.

Alkali and alkali-earth elements (simple metals)

For Li (and Be), a standard potential and a potential that treats the 1s shell as valence states are available (Li_sv, Be_sv). One should use the _sv potentials for many applications since their transferability is much higher than the standard potentials.

For the other alkali and alkali-earth elements, the semi-core s and p states should be treated as valence states as well. For lighter elements (Na-Ca), it is usually sufficient to treat the 2p and 3p states as valence states (_pv), respectively. For Rb-Sr, the 4s, 4p, and 5s, 5p states, must be treated as valence states (_sv).

Tip: For alkali and alkali-earth metals, the _sv variants should be chosen, other than for very light elements Na, Mg, K, and Ca, where _pv is usually sufficient.

p-elements

For Ga, Ge, In, Sn, Tl-At, the lower-lying d states should be treated as valence states (_d potential). For these elements, alternative potentials that treat the d states as core states are also available but should be used with great care.

d-elements

For the d elements, applies the same as for the alkali and earth-alkali metals: the semi-core p states and possibly the semi-core s states should be treated as valence states. In most cases, however, reliable results can be obtained even if the semi-core states are kept frozen.

When to switch from X_pv potentials to the X potentials depends on the required accuracy and the row for the 3d elements, even the Ti, V, and Cr potentials give reasonable results but should be used with uttermost care. 4d elements are the most problematic, and we advise using the X_pv potentials up to Tc_pv. For 5d elements the 5p states are rather strongly localized (below 3 Ry), since the 4f shell becomes filled. One can use the standard potentials starting from Hf, but we recommend performing test calculations. For some elements, X_sv potentials are available (,e.g., Nb_sv, Mo_sv, Hf_sv). These potentials usually have very similar energy cutoffs as the _pv potentials and can also be used. For HF-type and hybrid-functional calculations, we strongly recommend using the _sv and _pv potentials whenever possible.

Tip: As a rule of thumb the p states should be treated as valence states for d-elements, if their eigenenergy

\epsilon

lies above 3 Ry.

f-elements

Due to self-interaction errors, f electrons are not handled well by the presently available density functionals. In particular, partially filled f states are often incorrectly described. For instance, all f states are pinned at the Fermi-level, leading to large overbinding for Pr-Eu and Tb-Yb. The errors are largest at quarter and three-quarter filling, e.g., Gd is handled reasonably well since 7 electrons occupy the majority f shell. These errors are DFT and not VASP related.

Particularly problematic is the description of the transition from an itinerant (band-like) behavior observed at the beginning of each period to localized states towards the end of the period. For the 4f elements, this transition occurs already in La and Ce, whereas the transition sets in for Pu and Am for the 5f elements. A routine way to cope with the inabilities of present DFT functionals to describe the localized 4f electrons is to place the 4f electrons in the core. Such potentials are available and described below; however, they are expected to fail to describe magnetic properties arising f orbitals. Furthermore, PAW potentials in which the f states are treated as valence states are available, but these potentials are expected to fail to describe electronic properties when f electrons are localized. In this case, one might treat electronic correlation effects more carefully, e.g., by employing hybrid functionals or introducing on-site Coulomb interaction.

For some elements, soft versions (_s) are available as well. The semi-core p states are always treated as valence states, whereas the semi-core s states are treated as valence states only in the standard potentials. For most applications (oxides, sulfides), the standard version should be used since the soft versions might result in s ghost-states close to the Fermi-level (,e.g., Ce_s in ceria). The soft versions are, however, expected to be sufficiently accurate for calculations on intermetallic compounds.

Lanthanides with fixed valence

In addition, special GGA potentials are supplied for Ce-Lu, in which f electrons are kept frozen in the core, which is an attempt to treat the localized nature of f electrons. The number of f electrons in the core equals the total number of valence electrons minus the formal valency. For instance, according to the periodic table, Sm has a total of 8 valence electrons, i.e., 6 f electrons and 2 s electrons. In most compounds, Sm adopts a valency of 3; hence 5 f electrons are placed in the core when the pseudopotential is generated. The corresponding potential can be found in the directory Sm_3. The formal valency n is indicted by _n, where n is either 3 or 2. Ce_3 is, for instance, a Ce potential for trivalent Ce (for tetravalent Ce, the standard potential should be used).

Warning: f-elements are notoriously hard to describe with DFT due to self-interaction errors in the strongly localized orbitals. Placing some, or all, 4f electrons in the core can rectify this issue, but then the description of magnetism will fail and transferability will suffer.

Tip: If you are not interested in 4f-magnetism, and know the valency of your lanthanide, use the _2 or _3 potentials.

Test your setup

Even if you have taken a lot of care to optimize your pseudopotential choice, it is always good to perform some test calculations with other potentials, if necessary on a small prototype system. You might realize that you need extra accuracy, or that you are leaving performance on the table by using unnecessarily hard POTCARs for your problem.

Related tags and sections

POTCAR, Prepare a POTCAR, Available pseudopotentials

Theoretical background: Pseudopotentials, Theory: Pseudopotential basics, Projector-augmented-wave formalism