  We study aspects of an equivalent relation of the charge completeness in
six-dimensional (6D) $\mathcal{N}=(1,0)$ supergravity theory and a standard
assumption on the global structure of the gauge group involving F-theory
geometry, recently proved by Morrison and Taylor. We constructed and analyzed a
novel 6D supergravity theory, realized as F-theory, on an elliptically fibered
Calabi-Yau 3-fold. Our construction yields a novel 6D theory with Mordell-Weil
torsion $\mathbb{Z}_4\oplus\mathbb{Z}_4$. Furthermore, we deduce the gauge
group and matter fields arising in the 6D F-theory model on the constructed
elliptically fibered Calabi-Yau 3-fold. We also discuss the relations of the 6D
F-theory model constructed in this study to stable degeneration and the dual
heterotic string.
