For the Nb2O5-Li2O-Bi2O3-B2O3 glass system, optical, structure, mechanical gamma, and neutron radiation shielding aspects were examined comprehensively. The two probabilities of the bandgaps, direct and indirect transition, were evaluated. The absorbance of the recent glasses was increased as Nb2O5 increased. Moreover, the peak shifted to a longer wavelength as Nb2O5 increased. Our results show a decreasing behavior of both kinds of the bandgap. Adopting XCOM within 0.04–15 MeV, LAC and MAC were evaluated for all samples and calculated MAC values are in excellent compliance with deduced FLUKA code respective MAC outcomes. Zeff, HVL, and MFP values were estimated. MAC, Zeff, HVL, and MFP values depended on glass components and energy. Moreover, using equivalent atomic numbers (Zeq) and the geometric progression fitting procedure, EABF values were calculated up to 40 mfp, within 0.015–15 MeV. Comparatively higher density (4.9454 g/cm3), greater LAC, MAC, Zeff, Zeq, and lower HVL, MFP, EABF values achieved for 10Nb2O5-10Li2O-30Bi2O3-50B2O3 glass indicated it as a better gamma shield. Furthermore, the calculated ΣR shows that the 10Nb2O5-10Li2O-30Bi2O3-50B2O3 sample has commensurately greater ΣR (= 0.1744 cm−1).
