Declension table of ?śāntatva

Neuter	Singular	Dual	Plural
Nominative	śāntatvam	śāntatve	śāntatvāni
Vocative	śāntatva	śāntatve	śāntatvāni
Accusative	śāntatvam	śāntatve	śāntatvāni
Instrumental	śāntatvena	śāntatvābhyām	śāntatvaiḥ
Dative	śāntatvāya	śāntatvābhyām	śāntatvebhyaḥ
Ablative	śāntatvāt	śāntatvābhyām	śāntatvebhyaḥ
Genitive	śāntatvasya	śāntatvayoḥ	śāntatvānām
Locative	śāntatve	śāntatvayoḥ	śāntatveṣu

Compound śāntatva -

Adverb -śāntatvam -śāntatvāt