&FORCE_EVAL ! This section defines method for calculating energy and forces METHOD FIST ! Using Molecular Mechanics &MM &FORCEFIELD ! This section specifies forcefield parameters parm_file_name c2h2.top ! This file contains force field parameters (topology file) parmtype AMBER &SPLINE ! This section specifies parameters to set up the splines used in the nonboned interactions (both pair body potential and many body potential) EMAX_SPLINE 15.0 ! Specify the maximum value of the potential up to which splines will be constructed &END &END FORCEFIELD &POISSON ! This section specifies parameters for the Poisson solver &EWALD ! This section specifies parameters for the EWALD summation method (for the electrostatics) EWALD_TYPE SPME ! Smooth particle mesh using beta-Euler splines ALPHA .36 GMAX 128 ! Number of grid points &END EWALD &END POISSON &PRINT ! This section controls printing options &FF_INFO &END &FF_PARAMETER_FILE &END &END &END MM &SUBSYS ! This section defines the system &CELL ! Unit cell set up ABC 50 50 50 ! Lengths of the cell vectors A, B, and C &END CELL &COORD ! This section specify all the atoms and their coordinates H 0 0 0 C _C1_ 0 0 C _C2_ 0 0 H _H2_ 0 0 &END COORD &TOPOLOGY CHARGE_BETA ! Read MM charges from the BETA field of PDB file CONNECTIVITY AMBER ! Use AMBER topology file for reading connectivity CONN_FILE_NAME c2h2.top ! This file contains connectivity data &END TOPOLOGY &PRINT &TOPOLOGY_INFO AMBER_INFO &END &END &END SUBSYS &END FORCE_EVAL &GLOBAL ! Section with general information regarding which kind of simulation to perform an parameters for the whole PROGRAM PRINT_LEVEL LOW ! Global print level PROJECT c2h2 ! Name of the project. This word will appear as part of a name of all ouput files (except main ouput file, specified with -o option) RUN_TYPE ENERGY ! Calculating of energy for the fixed position of atoms &END GLOBAL