dist.f90

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!
!   CARACAL - Ring polymer molecular dynamics and rate constant calculations
!             on black-box generated potential energy surfaces
!
!   Copyright (c) 2023 by Julien Steffen (mail@j-steffen.org)
!                         Stefan Grimme (grimme@thch.uni-bonn.de) (QMDFF code)
!
!   Permission is hereby granted, free of charge, to any person obtaining a
!   copy of this software and associated documentation files (the "Software"),
!   to deal in the Software without restriction, including without limitation
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!   and/or sell copies of the Software, and to permit persons to whom the
!   Software is furnished to do so, subject to the following conditions:
!
!   The above copyright notice and this permission notice shall be included in
!   all copies or substantial portions of the Software.
!
!   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
!   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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!
!    function dist: calculate bond distance between at2 and at2
!
!    part of EVB
! 

function dist(at1,att2,xyz5)
use evb_mod
implicit none
integer::at1,att2
integer::i,j
real(kind=8)::dist
real(kind=8)::xyz5(3,natoms)
dist=sqrt((xyz5(1,att2)-xyz5(1,at1))*((xyz5(1,att2)-xyz5(1,at1)))+&
     &((xyz5(2,att2)-xyz5(2,at1))*((xyz5(2,att2)-xyz5(2,at1)))+&
     &((xyz5(3,att2)-xyz5(3,at1))*((xyz5(3,att2)-xyz5(3,at1))))))
return
end function dist