Explicitly correlated internally contracted multireference coupled-cluster singles and doubles theory: ic-MRCCSD(F12∗)

► We propose an explicitly correlated internally contracted multireference coupled-cluster method, ic-MRCCSD(F12∗). ► The F12 geminal contributions strongly improve the basis set convergence of the correlation energy. ► The extra computational cost in comparison to the parent method, ic-MRCCSD, is small. ► The ic-MRCCSD(F12∗)+(T) method produces very accurate results, even in combination with minimal active spaces.