How exactly does the drag coefficient alter Noose/Hoover equations?

I’m looking for the modified Noose/Hoover equations…can somebody give me a hint (link,paper, *.c-file and line#?)

regards.

I'm looking for the modified Noose/Hoover equations...can somebody give me
a hint (link,paper, *.c-file and line#?)

[[email protected]... src]$ grep -n drag fix_nh.cpp
69: drag = 0.0;
248: } else if (strcmp(arg[iarg],"drag") == 0) {
250: drag = force->numeric(FLERR,arg[iarg+1]);
251: if (drag < 0.0) error->all(FLERR,"Illegal fix nvt/npt/nph
command");
658: pdrag_factor = 1.0 - (update->dt * p_freq_max * drag / nc_pchain);
662: tdrag_factor = 1.0 - (update->dt * t_freq * drag / nc_tchain);
1667: pdrag_factor = 1.0 - (update->dt * p_freq_max * drag / nc_pchain);
1670: tdrag_factor = 1.0 - (update->dt * t_freq * drag / nc_tchain);
1721: eta_dot[ich] *= tdrag_factor;
1728: eta_dot[0] *= tdrag_factor;
1818: etap_dot[ich] *= pdrag_factor;
1825: etap_dot[0] *= pdrag_factor;
2205: omega_dot[i] *= pdrag_factor;
2223: omega_dot[i] *= pdrag_factor;