Line data    Source code

       1             : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       2             :    Copyright (c) 2011-2023 The plumed team
       3             :    (see the PEOPLE file at the root of the distribution for a list of names)
       4             : 
       5             :    See http://www.plumed.org for more information.
       6             : 
       7             :    This file is part of plumed, version 2.
       8             : 
       9             :    plumed is free software: you can redistribute it and/or modify
      10             :    it under the terms of the GNU Lesser General Public License as published by
      11             :    the Free Software Foundation, either version 3 of the License, or
      12             :    (at your option) any later version.
      13             : 
      14             :    plumed is distributed in the hope that it will be useful,
      15             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
      16             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      17             :    GNU Lesser General Public License for more details.
      18             : 
      19             :    You should have received a copy of the GNU Lesser General Public License
      20             :    along with plumed.  If not, see <http://www.gnu.org/licenses/>.
      21             : +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
      22             : #include "Colvar.h"
      23             : #include "core/ActionRegister.h"
      24             : 
      25             : namespace PLMD {
      26             : namespace colvar {
      27             : 
      28             : //+PLUMEDOC COLVAR VOLUME
      29             : /*
      30             : Calculate the volume of the simulation box.
      31             : 
      32             : \par Examples
      33             : 
      34             : The following input tells plumed to print the volume of the system
      35             : \plumedfile
      36             : vol: VOLUME
      37             : PRINT ARG=vol
      38             : \endplumedfile
      39             : 
      40             : */
      41             : //+ENDPLUMEDOC
      42             : 
      43             : 
      44             : class Volume : public Colvar {
      45             : 
      46             : public:
      47             :   explicit Volume(const ActionOptions&);
      48             : // active methods:
      49             :   void calculate() override;
      50             : /// Register all the keywords for this action
      51             :   static void registerKeywords( Keywords& keys );
      52             : };
      53             : 
      54             : PLUMED_REGISTER_ACTION(Volume,"VOLUME")
      55             : 
      56          15 : Volume::Volume(const ActionOptions&ao):
      57          15 :   PLUMED_COLVAR_INIT(ao)
      58             : {
      59             :   std::vector<AtomNumber> atoms;
      60          15 :   checkRead();
      61             : 
      62          30 :   addValueWithDerivatives(); setNotPeriodic();
      63          15 :   requestAtoms(atoms);
      64          15 : }
      65             : 
      66          20 : void Volume::registerKeywords( Keywords& keys ) {
      67          20 :   Action::registerKeywords( keys );
      68          20 :   ActionWithValue::registerKeywords( keys );
      69          20 :   ActionAtomistic::registerKeywords( keys );
      70          40 :   keys.setValueDescription("scalar","the volume of simulation box");
      71          20 : }
      72             : 
      73             : 
      74             : // calculator
      75         163 : void Volume::calculate() {
      76             : 
      77         163 :   double v=getBox().determinant();
      78         163 :   setBoxDerivatives(-v*Tensor::identity());
      79         163 :   setValue         (v);
      80         163 : }
      81             : 
      82             : }
      83             : }
      84             : 
      85             : 
      86             :