Hello. I've noticed a bug in the pressure computation when angle-angle interactions ('angleangle' function in improper_class2.cpp) are enabled. Currently (lammps-16Feb16) the energy/virial update call is

if (evflag)

ev_tally(i1,i2,i3,i4,nlocal,newton_bond,eimproper,

fabcd[0],fabcd[2],fabcd[3],

delxAB,delyAB,delzAB,delxBC,delyBC,delzBC,delxBD,delyBD,delzBD);

It should be called in the same way as in it's main function 'compute':

if (evflag)

ev_tally(i1,i2,i3,i4,nlocal,newton_bond,eimproper,

fabcd[0],fabcd[2],fabcd[3],

delxAB,delyAB,delzAB,delxBC,delyBC,delzBC,delxBD-delxBC,delyBD-delyBC,delzBD-delzBC);

Best regards, Ivan A. Strelnikov, ICP RAS.