Photodissociation of cold magnesium hydride ions MgH(+) leading to either Mg(+)+H or Mg+H(+) is simulated from first principles. The purpose is to study the possibility of single molecule control of the products in the presence of two laser fields. The system evolves on four electronic potential-energy curves, X(1) Sigma, A(1) Sigma, B(1) Pi, and C(1) Sigma. These potential-energy curves are ca...