tSPICA: Temperature- and Pressure-dependent Coarse-Grained Force Field for Organic Molecules

Mark Griffiths and Wataru Shinoda*

J. Chem. Info. Model. 59, 3829-3838 (2019).

Coarse-grained (CG) force fields optimized for a thermodynamic state typically lack transferability to different thermodynamic conditions. This work aims to improve the SPICA (formerly SDK) force field’s transferability at higher temperatures and pressures via a relatively simple scaling of the CG parameters while remaining consistent with SPICA at ambient conditions. The temperature- and pressure-dependent model, termed tSPICA, agrees better with experimental data over a wider range of temperature and pressure than the standard SPICA model for molecular assembly thermodynamic properties. tSPICA shows an improvement in response to increasing temperature for the test case of a C₁₂E₆ aqueous solution showing behavior nearer to that experimentally determined.