param.dat

implicit none
!! this file includes all parameter value to run the PIMC algorithm. 
!! Npt = no of particles and nrsb = quantum fluctuation (Main parameters)

integer, parameter :: nlev=4                             !! for bisection, no of levels, nb = no of beads. 
integer, parameter :: nb=2**(nlev-1)+1,Npt=57,Ndim=2,Npair=Npt*(Npt-1)/2, &
& maxnghbr = Npt                                         !! Npt = no of particles, maxnghbr = maximun number of neighbors.
integer, parameter :: nstep=10,nblkeq=10,nblk=10,Nbin=100, &
& Nbin2=Nbin*Nbin,nghbr=6, const = 100                   !! nstep, nblkeq, nblk = parameters for iteration 
                                                         !! Nbin = bining for correlations.
double precision,parameter :: nrsb = 0.010d0,lambda=nrsb*nrsb/2.d0, redt=0.0050d0  
                                                         !! nrsb = quantum parameter values
                                                         !! lambda = quantum kinectic energy value. 
                                                         !! redt = reducted temperature 
integer, parameter :: lcont=20, tbead = 50, nqmc=tbead
double precision,parameter :: beta=1/redt, tau=beta/dfloat(tbead), delta=0.01950d0
                                                         !! delta = displacement parameters for Monte-Carlo algorithm.

double precision :: pos_old(Ndim,tbead,Npt), pn(Ndim,nb,Npt),po(Ndim,nb,Npt), &
  & r_pp(tbead,Npair),rdist(Ndim,tbead,Npair),r_ppmove(nb,Npair), r_ppinit(nb,Npair), &
  & rdist_1pmove(Ndim,nb,Npair),r_pp_save(tbead,Npair),rdist_save(Ndim,tbead,Npair), r_pptrial(tbead,Npair)
double precision :: cmpos_old(Ndim,Npt),cmpos_new(Ndim,Npt),cmr_pp(Npair), & 
  &  cmr_ppsave(Npair),cmrdist(Ndim,Npair), cmrdist_save(Ndim,Npair), &
  & pos_save(Ndim,tbead,Npt)
double precision :: totKE,totPE,KEcm(Npt),PEcm(Npt), acceptpar(Npt), cmacceptpar(Npt)
double precision, parameter :: Rad_ini = 4.d0           !!  initial radius for generating random configuration

logical :: bisec_accept
logical :: totgr = .true., wrtlnd=.true. , wrtden=.true., wrturl=.true., & 
&  wrtenr = .true. , wrtbnd = .true.
logical :: wrtcmconfig=.true., wrtcmamp=.true., wrtcmgbr=.true., wrtcmgr=.true., &
& wrtcmlnd=.true.,wrtgrpt = .true.

!logical :: bisec = .true. ,cmdone = .true.

        common/position/pos_old,po,pn,cmpos_old,cmpos_new, pos_save
        common/distans/r_pp,rdist_1pmove,r_ppmove,r_ppinit,r_pptrial
        common/cmdistans/cmr_pp,cmr_ppsave
        common/totenergy/totKE,totPE,KEcm,PEcm
        common/accept/acceptpar,cmacceptpar