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0a472ff Jun 1, 2016
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  • For installation please refer to README.md

  • Do a vacuum calculation for your system first and save the wavefunction file WAVECAR by specifying LWAVE = .TRUE. in the INCAR file.

  • Start the solvation calculation from the vacuum WAVECAR, specify ISTART = 1 in the INCAR file.

  • The solvation parameters are read from the INCAR file.

  • In the simplest case the only parameter that need to be set is the solvation flag LSOL = .TRUE.

    This corresponds to the default case where the solvent is water with a 
    relative permittivity of 80. Note, The cavitation energy in the solvation 
    model requires a higher resolution than neeed for vacuum calculations. 
    So please make sure that ENCUT is large enough and also set PREC=Accurate.
  • The relative permittivity of the solvent can be changed from the default value of 78.4 for water to any value using the INCAR parameter EB_k, e.g. EB_k = 20.

  • You can also change the surface tension parameter tau in the INCAR file. For example, to neglect the the cavitation energy contribution, set TAU = 0 in the INCAR file. Note that you may have to increase the cutoff energy to converge the caviation energy because the grid must be fine enough to resolve the cavity surface.

  • Set LRHOB = .TRUE. if you would like to write out the bound charge density in the CHGCAR format. The file is named RHOB.

    Note: Inorder to keep the interface between the vaspsol and the rest 
    of the vasp ecosystem simple, the RHOB fileio is done within the module. This 
    means the RHOB file will be written in each scf iteration. This could slow down 
    the calculations for bigger systems. So it is reccomended that you do the solvation 
    calculations without this parameter and do another static calculation(starting 
    from the converged WAVECAR)with RHOB=.TRUE. if you wish to visualize the bound 
    charge. Sorry for the inconvenience. I will try to isolate the file io without 
    creating too much of a mess in the rest of the VASP code.
  • For examples, please see the Examples folder

  • Set LAMBDA_D_K(the debye length in Angstroms) parameter in the INCAR file to use the linearized Poisson-Boltzmann model(electrolyte model)

	The constant, FERMI_SHIFT, printed out to the stdout needs to be added to 
	the fermi level to get the alignment right(the sign of the shift becomes 
	apparent once you plot the x-y averaged local potential  in the z direction. 
	Without the shift the the electrostatic potential would not go to zero in 
	the bulk of the electrolyte as expected from the poisson-boltzmann solution).