<div dir="ltr">Hi everyone, <div> </div><div>I am trying to simulate a system with an isolated molecule, therefore I need a non-periodic setup. I have read the previous posts about the topic, but there are a number of questions open. They are both for the wavelet and the MT Poisson solver. </div><div> </div><div>1) System size</div><div>My simulations will be quite long (both MM and QM) and due to the movement of the molecule, to my understanding it needs to be avoided that molecule leaves the box. Will it be fine if I set the box size to 1000 Angstrom or is this not recommended? </div><div> </div><div>2) Periodic cells</div><div>This question is closely related to question 1). If I set the Poisson solver to non-periodic, could one set the CELL to periodic, and thus solve the problem that the molecule leaves the box?</div><div> </div><div>3) Ewald methods</div><div>Also closely related to question 1). If I set the box size to 1000, even with Ewald as Poisson solver the system should be effectively non-periodic due to the large distance, right? Would this be a plausible alternative to the MT or wavelet solvers?</div><div> </div><div>4) Mixed force evaluations</div><div>In the case that I have a mixed force evaluation setup and use the Wavelet solver (see the config file below), do I need to include the &CENTER_COORDINATES section also in the mixed force eval section, or only in the real force evaluation section?</div><div> </div><div>5) MT solver for periodic systems</div><div>Is the MT solver only for nonperiodic systems in CP2K, or does it also work for periodic systems? In the publication it is at least written it works for periodic systems and even with ewald/spme. </div><div> </div><div>Looking forward to hearing from you.</div><div> </div><div>Best wishes,</div><div>Jadzia</div><blockquote> &GLOBAL PROJECT system RUN_TYPE md PRINT_LEVEL medium &END global &MOTION &MD ENSEMBLE langevin &LANGEVIN GAMMA [fs^-1] 1.0E-3 # "Langevin" gamma (adapt for your system) &END LANGEVIN STEPS 5000000 TIMESTEP 0.5 TEMPERATURE 300.0 &END MD &PRINT &TRAJECTORY on FORMAT pdb FILENAME =cp2k.out.trajectory.pdb &EACH MD 10 &END EACH &END TRAJECTORY &END MOTION &MULTIPLE_FORCE_EVALS FORCE_EVAL_ORDER 2 3 MULTIPLE_SUBSYS true &END &FORCE_EVAL STRESS_TENSOR analytical METHOD mixed &MIXED MIXING_TYPE genmix &GENERIC VARIABLES a b MIXING_FUNCTION a+b &END @include cp2k.in.mapping &END &SUBSYS &TOPOLOGY &CENTER_COORDINATES &END CONNECTIVITY off COORDINATE pdb COORD_FILE_NAME system.pdb &END TOPOLOGY &CELL PERIODIC NONE ABC 20 20 20 &END CELL &END SUBSYS &END FORCE_EVAL &FORCE_EVAL STRESS_TENSOR analytical METHOD fist &MM &FORCEFIELD PARM_FILE_NAME system1.prm PARMTYPE chm &SPLINE EMAX_SPLINE 100000 RCUT_NB 12. &END &END FORCEFIELD &POISSON POISSON_SOLVER WAVELET PERIODIC NONE &EWALD EWALD_TYPE NONE &END EWALD &END POISSON &END MM &SUBSYS &CELL PERIODIC NONE ABC 20 20 20 &END CELL &TOPOLOGY &CENTER_COORDINATES &END COORDINATE pdb COORD_FILE_NAME system1.pdb CONN_FILE_FORMAT psf CONN_FILE_NAME system1.psf &END TOPOLOGY @include cp2k.in.sub.kind.element.c36 &END SUBSYS &END FORCE_EVAL &FORCE_EVAL STRESS_TENSOR analytical METHOD fist &MM &FORCEFIELD PARM_FILE_NAME system2.prm PARMTYPE chm &SPLINE EMAX_SPLINE 100000 RCUT_NB 12. &END &END FORCEFIELD &POISSON POISSON_SOLVER WAVELET PERIODIC NONE &EWALD EWALD_TYPE NONE &END EWALD &END POISSON &END MM &SUBSYS &CELL PERIODIC NONE ABC 20 20 20 &END CELL &TOPOLOGY &CENTER_COORDINATES &END COORDINATE pdb COORD_FILE_NAME system2.pdb CONN_FILE_FORMAT psf CONN_FILE_NAME system2.psf &END TOPOLOGY @include cp2k.in.sub.kind.element.c36 &END SUBSYS &END FORCE_EVAL</blockquote></div>