Solvation energy
Checking the Solvation energy checkbox on the Properties tab causes calculation of the free energy of solvation, as a separate CASTEP run. This additional run evaluates the energy of a molecule in a box both in vacuum and in the presence of an implicit solvent. Then CASTEP produces the energy of solvation from these results.
There are certain limitations for solvation energy calculations:
- The system must represent a molecule in a box.
- Symmetry of the system must be P1.
- Calculations must not include spin-polarization.
- Stress calculations are not available.
You can specify the options for the solvation energy calculation on the Solvent tab of the CASTEP Electronic Options dialog.
Use at least a Fine FFT grid Density for solvation calculations; the Precise density is even better. You can specify the FFT grid Density on the
Basis tab of the CASTEP Electronic Options dialog. Also use an increased value of Augmentation density scaling factor, for example 1.5-2.0 instead of the default value of 1.0.
An increased FFT density and energy cutoff can help to eliminate convergence errors for the multigrid solver for electrostatics in a solvent.
Access methods
| Menu | Modules | CASTEP | Calculation | Properties | Solvation energy |
| Toolbar |
 | Calculation | Properties | Solvation energy
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