Velocities were taken from a Maxwell distribution at 500 K
GB parameter(s) missing or negative for atom type 'MG'
GB parameter(s) missing or negative for atom type 'CAL'
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Program gmx grompp, VERSION 5.1.2
Source code file: /export/src/gromacs-5.1.2/src/gromacs/gmxpreprocess/grompp.c, line: 1303
Fatal error:
Can't do GB electrostatics; the implicit_genborn_params section of the forcefield is missing parameters for 2 atomtypes or they might be negative.