# read restart files generated by in.forward, and run long equilibration simulations
# set different lambda values

variable        NAME index ar
log             ${NAME}.log
variable        infile index data.${NAME}
variable        mytemp index 90
variable        lambda equal 0.0

units           real
atom_style      full
pair_style      hybrid/overlay lj/cut 10 coul/cut 10 gauss 10

kspace_style    none

#read_data       ${infile}
read_restart     restart.0
pair_modify     tail yes

pair_coeff      *     *   none
pair_coeff      1 1 lj/cut 0.238122 3.405
pair_coeff      1 1 coul/cut 10
pair_coeff      1 2 gauss 1.0674  0.9

neighbor        2.0 bin
neigh_modify    delay 0 every 1 check yes page 1000000 one 20000 
timestep        1


## variables for TI   
#variable lambda equal ramp(0,1)
variable m equal 1
variable n equal 2
variable eta equal 0.1

variable scale_vdw equal (1+v_lambda*(${eta}-1))^$m

variable dscale_vdw equal (${eta}-1)


## for gauss
variable lmd equal v_lambda
variable gauss_scl equal v_lmd
variable dgauss_scl equal 1

group   mobile type <> 1 1
group   stat   type <> 2 2


velocity        all zero linear units box


fix             1 mobile nvt temp ${mytemp} ${mytemp} 100.0
dump            1 all custom 10000 ${NAME}.lammpstrj id type x y z

## TI
fix            2 mobile adapt 1 pair lj/cut epsilon 1*1 1*1 v_scale_vdw scale yes
compute        1 all ti lj/cut 1*1 v_scale_vdw v_dscale_vdw tail 1*1 v_scale_vdw v_dscale_vdw

fix             6 all adapt 1 pair gauss a 1 2 v_gauss_scl scale yes
compute         6 all ti gauss * v_gauss_scl v_dgauss_scl
compute         gauss all pair gauss
variable        occ equal c_gauss[1]
variable        com1 equal c_1
variable        com2 equal c_6


thermo_style    custom step vol temp press ke pe etotal enthalpy evdwl etail v_lambda v_scale_vdw v_dscale_vdw v_occ c_1 c_6 c_gauss lx ly lz
thermo          200
fix             TI_data all print 200 "${lambda}    ${scale_vdw}    ${gauss_scl} ${com1}  ${com2}" file TI.txt

restart         50000 restart.${NAME}.1 restart.${NAME}.2
run             2000000

write_restart   restart.${NAME}