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module charge_charge |
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|
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use force_globals |
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use definitions |
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use atype_module |
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use vector_class |
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use simulation |
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use status |
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#ifdef IS_MPI |
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use mpiSimulation |
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#endif |
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implicit none |
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|
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PRIVATE |
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real(kind=dp), save :: ecr = 0.0_DP |
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real(kind=dp), save :: rt = 0.0_DP |
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real(kind=dp), save :: pre = 0.0_DP |
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logical, save :: haveCutoffs = .false. |
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logical, save :: haveChargeMap = .false. |
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|
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public::setCutoffsCharge |
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public::do_charge_pair |
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|
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type :: ChargeList |
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real(kind=DP) :: charge = 0.0_DP |
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end type ChargeList |
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|
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type(ChargeList), dimension(:), allocatable :: ChargeMap |
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|
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contains |
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|
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subroutine setCutoffsCharge(this_ecr, this_rt) |
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real(kind=dp), intent(in) :: this_ecr, this_rt |
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ecr = this_ecr |
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rt = this_rt |
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|
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! pre converts from fundamental charge to kcal/mol |
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pre = 332.06508_DP |
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|
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haveCutoffs = .true. |
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|
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return |
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end subroutine setCutoffsCharge |
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|
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subroutine createChargeMap(status) |
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integer :: nAtypes |
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integer :: status |
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integer :: i |
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real (kind=DP) :: thisCharge |
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logical :: thisProperty |
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|
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status = 0 |
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|
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nAtypes = getSize(atypes) |
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|
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if (nAtypes == 0) then |
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status = -1 |
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return |
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end if |
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|
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if (.not. allocated(ChargeMap)) then |
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allocate(ChargeMap(nAtypes)) |
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endif |
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|
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do i = 1, nAtypes |
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|
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call getElementProperty(atypes, i, "is_Charge", thisProperty) |
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|
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if (thisProperty) then |
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call getElementProperty(atypes, i, "charge", thisCharge) |
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ChargeMap(i)%charge = thisCharge |
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endif |
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|
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end do |
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|
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haveChargeMap = .true. |
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|
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end subroutine createChargeMap |
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|
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|
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subroutine do_charge_pair(atom1, atom2, d, rij, r2, pot, f, & |
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do_pot, do_stress) |
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|
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logical :: do_pot, do_stress |
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|
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integer atom1, atom2, me1, me2, id1, id2 |
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integer :: localError |
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real(kind=dp) :: rij, r2, q1, q2 |
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real(kind=dp) :: drdx, drdy, drdz, dudr, fx, fy, fz |
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real(kind=dp) :: taper, dtdr, vterm |
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|
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real( kind = dp ) :: pot |
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real( kind = dp ), dimension(3) :: d |
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real( kind = dp ), dimension(3,nLocal) :: f |
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|
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if (.not. haveCutoffs) then |
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write(default_error,*) 'charge-charge does not have cutoffs set!' |
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return |
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endif |
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|
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if (.not.haveChargeMap) then |
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localError = 0 |
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call createChargeMap(localError) |
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if ( localError .ne. 0 ) then |
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call handleError("charge-charge", "ChargeMap creation failed!") |
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return |
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end if |
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endif |
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|
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#ifdef IS_MPI |
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me1 = atid_Row(atom1) |
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me2 = atid_Col(atom2) |
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#else |
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me1 = atid(atom1) |
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me2 = atid(atom2) |
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#endif |
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|
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q1 = ChargeMap(me1)%charge |
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q2 = ChargeMap(me2)%charge |
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|
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if (rij.le.ecr) then |
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|
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if (rij.lt.rt) then |
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taper = 1.0d0 |
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dtdr = 0.0d0 |
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else |
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taper = (ecr + 2.0d0*rij - 3.0d0*rt)*(ecr-rij)**2/ ((ecr-rt)**3) |
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dtdr = 6.0d0*(rij*rij - rij*rt - rij*ecr +ecr*rt)/((ecr-rt)**3) |
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endif |
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|
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vterm = pre * q1 * q2 / rij |
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|
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dudr = vterm * ( dtdr - taper / rij ) |
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|
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drdx = d(1) / rij |
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drdy = d(2) / rij |
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drdz = d(3) / rij |
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|
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fx = dudr * drdx |
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fy = dudr * drdy |
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fz = dudr * drdz |
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|
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#ifdef IS_MPI |
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if (do_pot) then |
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pot_Row(atom1) = pot_Row(atom1) + vterm*taper*0.5 |
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pot_Col(atom2) = pot_Col(atom2) + vterm*taper*0.5 |
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endif |
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|
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f_Row(1,atom1) = f_Row(1,atom1) + fx |
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f_Row(2,atom1) = f_Row(2,atom1) + fy |
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f_Row(3,atom1) = f_Row(3,atom1) + fz |
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|
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f_Col(1,atom2) = f_Col(1,atom2) - fx |
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f_Col(2,atom2) = f_Col(2,atom2) - fy |
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f_Col(3,atom2) = f_Col(3,atom2) - fz |
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|
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#else |
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|
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if (do_pot) pot = pot + vterm*taper |
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|
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f(1,atom1) = f(1,atom1) + fx |
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f(2,atom1) = f(2,atom1) + fy |
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f(3,atom1) = f(3,atom1) + fz |
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|
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f(1,atom2) = f(1,atom2) - fx |
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f(2,atom2) = f(2,atom2) - fy |
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f(3,atom2) = f(3,atom2) - fz |
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|
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#endif |
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|
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if (do_stress) then |
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|
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#ifdef IS_MPI |
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id1 = tagRow(atom1) |
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id2 = tagColumn(atom2) |
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#else |
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id1 = atom1 |
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id2 = atom2 |
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#endif |
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|
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if (molMembershipList(id1) .ne. molMembershipList(id2)) then |
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|
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! because the d vector is the rj - ri vector, and |
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! because fx, fy, fz are the force on atom i, we need a |
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! negative sign here: |
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|
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tau_Temp(1) = tau_Temp(1) - d(1) * fx |
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tau_Temp(2) = tau_Temp(2) - d(1) * fy |
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tau_Temp(3) = tau_Temp(3) - d(1) * fz |
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tau_Temp(4) = tau_Temp(4) - d(2) * fx |
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tau_Temp(5) = tau_Temp(5) - d(2) * fy |
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tau_Temp(6) = tau_Temp(6) - d(2) * fz |
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tau_Temp(7) = tau_Temp(7) - d(3) * fx |
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tau_Temp(8) = tau_Temp(8) - d(3) * fy |
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tau_Temp(9) = tau_Temp(9) - d(3) * fz |
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|
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virial_Temp = virial_Temp + & |
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(tau_Temp(1) + tau_Temp(5) + tau_Temp(9)) |
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|
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endif |
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endif |
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|
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endif |
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return |
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end subroutine do_charge_pair |
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|
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end module charge_charge |
