Table 3. Selected geometric parameters (, ) for (3) .

S1C2	1.676(3)	S2C12	1.675(2)
Si1N1	1.817(2)	Si2N11	1.804(2)
Si1C22	1.841(3)	Si2C24	1.827(3)
Si1C20	1.846(3)	Si2C23	1.830(4)
Si1C21	1.850(3)	Si2C25	1.841(3)
N1Si1C22	108.72(12)	N11Si2C24	111.21(15)
N1Si1C20	107.62(12)	N11Si2C23	105.51(15)
C22Si1C20	109.24(16)	C24Si2C23	113.3(2)
N1Si1C21	109.12(13)	N11Si2C25	109.27(13)
C22Si1C21	108.81(18)	C24Si2C25	106.95(19)
C20Si1C21	113.23(16)	C23Si2C25	110.6(2)
C2N1Si1	122.00(16)	C12N11Si2	123.12(16)
C8N1Si1	130.56(17)	C18N11Si2	128.88(17)
N3C2S1	125.48(19)	N13C12S2	125.02(19)
N1C2S1	126.65(18)	N11C12S2	127.12(18)
C22Si1N1C2	176.3(2)	C24Si2N11C12	56.7(3)
C20Si1N1C2	65.5(2)	C23Si2N11C12	66.5(2)
C21Si1N1C2	57.8(2)	C25Si2N11C12	174.5(2)
C22Si1N1C8	1.1(3)	C24Si2N11C18	133.4(3)
C20Si1N1C8	117.1(2)	C23Si2N11C18	103.4(3)
C21Si1N1C8	119.6(2)	C25Si2N11C18	15.6(3)
C9N3C2S1	179.14(18)	C19N13C12S2	179.11(18)
Si1N1C2N3	177.32(16)	Si2N11C12N13	171.28(16)
C8N1C2S1	178.90(19)	C18N11C12S2	179.38(19)
Si1N1C2S1	3.2(3)	Si2N11C12S2	8.8(3)
Si1N1C8C9	177.06(17)	Si2N11C18C17	8.5(5)
Si1N1C8C7	3.0(4)	Si2N11C18C19	171.09(18)