HESSEMAT: Difference between revisions

From VASP Wiki
No edit summary
No edit summary
 
(3 intermediate revisions by the same user not shown)
Line 1: Line 1:
{{FILE|HESSEMAT}} defines the Hesse matrix in Cartesian coordinates (<math>\underline{\mathbf{H}}^\mathbf{x}</math> ) for the use in  [[:Category:Thermodynamic integration with harmonic reference|Thermodynamic integration with harmonic reference]].
{{FILE|HESSEMAT}} defines the Hesse matrix in Cartesian coordinates (<math>\underline{\mathbf{H}}^\mathbf{x}</math> ) for the use in  [[Thermodynamic integration#Thermodynamic integration with harmonic reference|Thermodynamic integration with harmonic reference]].
For a system containing <math> N</math> atoms, {{FILE|HESSEMAT}} has <math>(3N+1)(N+1)</math> lines.
For a system containing <math> N</math> atoms, {{FILE|HESSEMAT}} has <math>(3N+1)(N+1)</math> lines.
The first line specifies potential energy <math>V_{0,\mathbf{x}}(\mathbf{x}_0)</math>  (in eV) of the relaxed system for which <math>\underline{\mathbf{H}}^\mathbf{x}</math> is computed.
The first line specifies potential energy <math>V_{0,\mathbf{x}}(\mathbf{x}_0)</math>  (in eV) of the relaxed system for which <math>\underline{\mathbf{H}}^\mathbf{x}</math> is computed.
The following <math>3N</math> lines are reserved for positions in fractional coordinates of all atoms constituting the system, whereby each line should contain three components of position vector of a single atom. The remaining part of {{FILE|HESSEMAT}} consist of <math>3N</math> block of <math>N+1</math> lines each.
The following <math>3N</math> lines are reserved for positions in fractional coordinates of all atoms constituting the system, whereby each line should contain three components of position vector of a single atom. The remaining part of {{FILE|HESSEMAT}} consist of <math>3N</math> block of <math>N+1</math> lines each.
Each block contains information related to a single eigenmode of <math>\underline{\mathbf{H}}^\mathbf{x}</math>: the first line specified the  eigenvalue (in eV/<math>{\AA}^2</math>) and remaining and <math>N</math> lines the corresponding eigenvector (in Cartesian coordinates) in a 3-column format.
Each block contains information related to a single eigenmode of <math>\underline{\mathbf{H}}^\mathbf{x}</math>: the first line specified the  eigenvalue (in eV/<math>{\AA}^2</math>) and remaining and <math>N</math> lines the corresponding eigenvector (in Cartesian coordinates) in a 3-column format.
How to run thermodynamic integration calculations is given [[Thermodynamic integration calculations#Alternative way of thermodynamic integration for harmonic solid|here]].
== Related tags and articles ==
{{TAG|TILAMBDA}}, {{TAG|REPORT}}


[[Category:Advanced molecular-dynamics sampling]][[Category:Files]]
[[Category:Advanced molecular-dynamics sampling]][[Category:Files]]

Latest revision as of 14:10, 17 October 2024

HESSEMAT defines the Hesse matrix in Cartesian coordinates ( ) for the use in Thermodynamic integration with harmonic reference. For a system containing atoms, HESSEMAT has lines. The first line specifies potential energy (in eV) of the relaxed system for which is computed. The following lines are reserved for positions in fractional coordinates of all atoms constituting the system, whereby each line should contain three components of position vector of a single atom. The remaining part of HESSEMAT consist of block of lines each. Each block contains information related to a single eigenmode of : the first line specified the eigenvalue (in eV/) and remaining and lines the corresponding eigenvector (in Cartesian coordinates) in a 3-column format.

How to run thermodynamic integration calculations is given here.

Related tags and articles

TILAMBDA, REPORT