satvikkg
commented
1 year ago Can you please share the link from where you got the file. It will give me more information onto how we can solve the problem as to why this itp file is not working in your case.
ramya-khandika
[ moleculetype ] ; molname nrexcl SOL 2
[ atoms ] ; id at type res nr res name at name cg nr charge mass 1 OW_opc 1 SOL OW 1 0 16.00000 2 HW_opc 1 SOL HW1 1 0.67910 1.00800 3 HW_opc 1 SOL HW2 1 0.67910 1.00800 4 MW 1 SOL MW 1 -1.35820 0.00000
ifndef FLEXIBLE
[ settles ] ; i funct doh dhh ;1 1 0.09572 0.15139 ;TIP4Pew parameter 1 1 0.087240 0.1371163197 ;OPC parameter
else
[ bonds ] ; i j funct length force.c. ;1 2 1 0.09572 502416.0 0.09572 502416.0 ;TIP4Pew parameter ;1 3 1 0.09572 502416.0 0.09572 502416.0 ;TIP4Pew parameter 1 2 1 0.087240 502416.0 0.087240 502416.0 ;OPC parameter 1 3 1 0.087240 502416.0 0.087240 502416.0 ;OPC parameter
[ angles ] ; i j k funct angle force.c. ;2 1 3 1 104.52 628.02 104.52 628.02 ;TIP4Pew parameter 2 1 3 1 103.6 628.02 104.52 628.02 ;OPC parameter
endif
[ virtual_sites3 ] ; Vsite from funct a b ;4 1 2 3 1 0.106676721 0.106676721 ;TIP4Pew parameter 4 1 2 3 1 0.14772952 0.14772952 ;OPC parameter
[ exclusions ] 1 2 3 4 2 1 3 4 3 1 2 4 4 1 2 3
; The position of the virtual site is computed as follows: ; ; O ;
; V ;
; H H ; ; Ewald tip4p: ; const = distance (OV) / [ cos (angle(VOH)) distance (OH) ] ; 0.0125 nm / [ cos (52.26 deg) 0.09572 nm ] ; then a = b = 0.5 const = 0.106676721 ; ; Vsite pos x4 = x1 + a(x2-x1) + b(x3-x1) ; ; Ewald OPC: ; const = distance (OV) / [ cos (angle(VOH)) distance (OH) ] ; 0.01594 nm / [ cos (51.80 deg) 0.08724 nm ] ; then a = b = 0.5 const = 0.14772952 ; ; Vsite pos x4 = x1 + a(x2-x1) + b(x3-x1)