src/gromacs/gmxana/thermochemistry.h

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
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   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
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  35 /*! \internal \file
  36  * \brief
  37  * Code for computing entropy from eigenvalues
  38  *
  39  * \author David van der Spoel <david.vanderspoel@icm.uu.se>
  40  */
  41 #ifndef GMXANA_ENTROPY_H
  42 #define GMXANA_ENTROPY_H
  43
  44 #include "gromacs/math/vec.h"
  45 #include "gromacs/utility/basedefinitions.h"
  46
  47 /*! \brief Compute entropy using Schlitter formula
  48  *
  49  * Computes entropy for a molecule / molecular system using the
  50  * algorithm due to Schlitter (Chem. Phys. Lett. 215 (1993)
  51  * 617-621).
  52  * The input should be eigenvalues from a covariance analysis,
  53  * the units of the eigenvalues are those of energy.
  54  *
  55  * \param[in] n            Number of entries in the eigval array
  56  * \param[in] eigval       The eigenvalues
  57  * \param[in] temperature  Temperature (K)
  58  * \param[in] linear       True if this is a linear molecule (typically a diatomic molecule).
  59  * \return the entropy (J/mol K)
  60  */
  61 real calc_entropy_schlitter(int      n,
  62                             real     eigval[],
  63                             real     temperature,
  64                             gmx_bool linear);
  65
  66 /*! \brief Compute entropy using Quasi-Harmonic formula
  67  *
  68  * Computes entropy for a molecule / molecular system using the
  69  * Quasi-harmonic algorithm (Macromolecules 1984, 17, 1370).
  70  * The input should be eigenvalues from a normal mode analysis.
  71  * In both cases the units of the eigenvalues are those of energy.
  72  *
  73  * \param[in] n            Number of entries in the eigval array
  74  * \param[in] eigval       The eigenvalues
  75  * \param[in] temperature  Temperature (K)
  76  * \param[in] linear       True if this is a linear molecule (typically a diatomic molecule).
  77  * \return the entropy (J/mol K)
  78  */
  79 real calc_entropy_quasi_harmonic(int      n,
  80                                  real     eigval[],
  81                                  real     temperature,
  82                                  gmx_bool linear);
  83
  84 #endif