Table 4. Comparison of third order susceptibility with other crystals.

Crystal	Third order susceptibility (χ(3)) esu	References
Potassium succinate–succinic acid	6.4649 × 10−9	42
Potassium tri-hydrogen di-succinate	5.9056 × 10−5	25
Sodium boro succinate	3.5 × 10−4	43
Rubidium hydrogen succinate hydrate	4.86331 × 10−9	Present work