SCALEE

SCALEE = [real]
Default: SCALEE = 1 

Description: This tag specifies the scaling constant of the energies and forces.

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In thermodynamic integration the free energy difference between two systems is defined as

$\Delta F = \int\limits_{0}^{1} d\lambda \langle U_{1} - U_{0} \rangle$

where

For thermodynamic integration this parameter controls the coupling parameter $\lambda$.

This parameter is only used if SCALEE$\ne$1.

Usually the thermodynamic integration is carried out from the ideal gas to the liquid state.

If the file DYNMATFULL exists in the calculation directory (from a previous calculation using PHON_NSTRUCT=-1) and SCALEE$\ne$1, the second order Hessian matrix is added to the force and thermodynamic integration from a harmonic model to a fully interacting system is carried out. Here the Hamiltonian for a certain integration point along the thermodynamic integration pathway is given as

$H_{\lambda} = (1-\lambda) H_{\mathrm{harmonic}} + \lambda H_{\mathrm{ab initio}}.$

Related Tags and Sections

VCAIMAGES, IMAGES, NCORE IN IMAGE1, PHON_NSTRUCT

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