Table 3. Raman tensor elements obtained from modeling the polarization dependence of the experimental Raman scattering intensity and from ab-initio calculations, normalized to a value of 1000 for the highest Raman polarizability.

Phonon mode	Experiment				Theory
	a	b	c	d	a	b	c	d
	19	−59	14	13	79	−70	21	9
	100	146	119	0	142	214	150	−34
	187	445	311	27	154	431	272	−16
	111	147	135	128	124	113	154	146
	441	111	320	−5	479	12	349	−18
	357	289	338	158	320	358	293	146
	47	−300	327	−52	31	−369	−241	9
	59	393	240	−135	55	414	53	−164
	408	77	118	325	468	61	21	364
	1000	353	0	−283	1000	248	−191	−409

Experimental values for c are given as positive values, but may as well be negative from experimental results.