+ if ((zj.gt.bordlipbot)
+ &.and.(zj.lt.bordliptop)) then
+C the energy transfer exist
+ if (zj.lt.buflipbot) then
+C what fraction I am in
+ fracinbuf=1.0d0-
+ & ((positi-bordlipbot)/lipbufthick)
+C lipbufthick is thickenes of lipid buffore
+ sslipj=sscalelip(fracinbuf)
+ ssgradlipj=-sscagradlip(fracinbuf)/lipbufthick
+ elseif (zi.gt.bufliptop) then
+ fracinbuf=1.0d0-((bordliptop-positi)/lipbufthick)
+ sslipj=sscalelip(fracinbuf)
+ ssgradlipj=sscagradlip(fracinbuf)/lipbufthick
+ else
+ sslipj=1.0d0
+ ssgradlipj=0.0
+ endif
+ else
+ sslipj=0.0d0
+ ssgradlipj=0.0
+ endif
+ aa=aa_lip(itypi,itypj)*(sslipi+sslipj)/2.0d0
+ & +aa_aq(itypi,itypj)*(2.0d0-sslipi+sslipj)/2.0d0
+ bb=bb_lip(itypi,itypj)*(sslipi+sslipj)/2.0d0
+ & +bb_aq(itypi,itypj)*(2.0d0-sslipi+sslipj)/2.0d0
+