A molecular crystal form of (R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid is characterized by at least one of: (a) an X-ray powder diffraction (“XRPD”) spectrum that comprises peaks at 2θ angles of 10.6, 15, 19.7, 21.1, and 22°±0.2°； (b) a DSC melting peak at 288℃； (c) a13C NMR spectrum having peaks at 23.3, 27.7, 41.1, 54.5, 116.6, and 153.5 ppm； and (d) pKa values of 5.65 and 9.91.本發明係關於一種(R)-(+)-7-(3-胺基-2,3,4,5,6,7-六氫-1H-氮雜呯-1-基)-6-氟-8-氯-1,4-二氫-4-側氯基喹啉-3-羧酸之分子結晶形式，其特徵為以下至少一項：(a)其X-射線粉末繞射(「XRPD」)光譜包括出現在2θ角：10.6、15、19.7、21.1及22°±0.2°之波峰；(b)其DSC熔融峰值為288℃；(c)其13C NMR光譜具有出現於23.3、27.7、41.1、54.5、116.6、及153.5ppm之波峰；及(d)其pKa值為5.65及9.91。
