Table 2. Comparison of piezoelectric coefficients of other alkali metals[].

Crystal	Piezoelectric charge coefficient pC N−1	References
Lithium sulfate monohydrate (LSMH)	6	36
Sodium acid phthalate hemihydrate	1.45	37
Potassium hydrogen phthalate	0.92	38
Ammonium dihydrogen phosphate (ADP)	1.80	39
Rubidium hydrogen succinate hydrate (RbHSH)	13	Present work