The value of \[\Delta H{}^\circ \] for the hypothetical reaction, \[{{A}_{2}}B\left( s \right)\,\,\to \,\,2A\left( s \right)+\frac{1}{2}\text{ }{{B}_{2}}\,\,\left( g \right)\text{ }is,\,\,+\,\,7.3\text{ }kJ\] The value of \[\Delta U{}^\circ \] for the reaction is -