946 
be considered as lying in their mutual spheres of action will be 
characterized again by the distance 7 of their centres, the angles 
0, and 9, of the quadrupole axes with the line connecting the 
centres and by the angle p (see Fig. 2). The energy of this pair 
will be obtained by adding to the quadrupole term given in the 
cited paper: 
3 3 
gb1 => {1 — 5 cos* A, — 5 cos? A, — 15 cos* A, cos? 0, + 
yr 
+ 2 (4 cos 0, cos 0, + sin O, sin 8, cos p)°} . (4) 
the induced term: 
nen Aleta) oon ree 
WITT gigs bsin* 0, + sin“ 0, + 4c0s* 0, +-4¢08*O,} . (5) 
Still a term might be added, due to the forces exerted by the 
two induced bipoles on each other. This term would contain a’. 
For the moment we shall however omit terms with @’. 
From Leiden Suppl. N°. 39a we take the notations 
marine 
TE | | 
where for shortness sake v will be written for ,v, this being the 
potential energy of the pair of molecules when in contact with the 
mentioned (l.c.) direetions of the quadrupole axes for the case that 
only the quadrupole attraction is taken into consideration. 
Further 
v 65 = diameter of the molecule, . . . (6) 
GC 
eh =e oa Win eren die 
where heee 
Wi A Bicosap. tr O c0s AP ae a EN 
when 
A = 2(1—3 cos? 8.) (1 —3 cos* O,) | 
B= 16 sin O, cos 0, sin 0, cos 8, | hs RS etat 
C = sin’ 0, sin’ 0, 
We now introduce ; 
X = sin' 0, + sin‘ 0, + 4 cos‘ 0, + 40086, . . . (10) 
Then we have 
: Sen Jato’ 
SU a th os ie Teeter aan ee 
The second virial coefficient becomes 
heey 
Ba zn(; wot P') ee. eel) 
2 \8 
with 
