Study of electron scattering from $${{\mathrm {CH}}}_{{4}}^{+}$$, $${{\mathrm {NH}}}_{{3}}^{+}$$, $${\mathrm {H}}_{{2}}{\mathrm {O}}^{+}$$, $${{\mathrm {NH}}}_{{4}}^{+}$$ and $${\mathrm {H}}_{{3}}{\mathrm {O}}^{+}$$ molecular ions with an analytic static potential approach