It is a variational method that uses a wave function that is a linear combination of Slater determinants.

It is a perturbative method that starts from a Hartree-Fock reference wave function.

It is a non-variational method that uses a wave function that is a product of geminals.

It is a semi-empirical method that uses experimental data to parameterize the wave function.

It is an operator that creates a pair of electrons in the same spatial orbital.

It is an operator that creates a pair of electrons with opposite spins in different spatial orbitals.

It is an operator that creates a pair of electrons with the same spin in different spatial orbitals.

It is an operator that creates a pair of electrons with opposite spins in the same spatial orbital.

It is an operator that exponentiates the cluster operator.

It is an operator that exponentiates the Hamiltonian operator.

It is an operator that exponentiates the Fock operator.

It is an operator that exponentiates the correlation operator.

It is equal to the number of electrons in the system.

It is equal to the number of occupied orbitals in the system.

It is equal to the number of virtual orbitals in the system.

It is equal to the number of pairs of electrons in the system.

It scales as $N^4$, where $N$ is the number of electrons in the system.

It scales as $N^5$, where $N$ is the number of electrons in the system.

It scales as $N^6$, where $N$ is the number of electrons in the system.

It scales as $N^7$, where $N$ is the number of electrons in the system.

It is the most accurate method for calculating the electronic structure of molecules.

It is one of the most accurate methods for calculating the electronic structure of molecules.

It is a moderately accurate method for calculating the electronic structure of molecules.

It is a low-accuracy method for calculating the electronic structure of molecules.

It is used to calculate the electronic structure of molecules.

It is used to calculate the properties of molecules.

It is used to calculate the reaction rates of molecules.

It is used to calculate the spectra of molecules.

It is a computationally expensive method.

It is not applicable to large molecules.

It is not applicable to molecules with strong correlation.

It is not applicable to molecules with open-shell configurations.

The development of new methods for reducing the computational cost of Coupled Cluster Theory.

The development of new methods for applying Coupled Cluster Theory to large molecules.

The development of new methods for applying Coupled Cluster Theory to molecules with strong correlation.

The development of new methods for applying Coupled Cluster Theory to molecules with open-shell configurations.

It will continue to be a powerful tool for studying the behavior of molecules at the quantum level.

It will be replaced by more accurate methods.

It will be replaced by less computationally expensive methods.

It will be replaced by methods that are applicable to a wider range of molecules.