These empirical methods were replaced in the 1960s by semi-empirical methods such as CNDO.

Large molecules can be studied by semi-empirical approximate methods.

Density functional methods and semi-empirical methods are variants on the major theme.

A semi-empirical method for the determination of reactivity ratios is called the Q-e scheme.

Second, engineering research employs many semi-empirical methods that are foreign to pure scientific research, one example being the method of parameter variation.

On the calculations: quantum chemical studies use also semi-empirical and other methods based on quantum mechanical principles, and deal with time dependent problems.

The MRCI method can also be implemented in semi-empirical methods.

However, semi-empirical methods were also applied to solids and nanostructures but with different parameterization.

The table below shows some software packages that carry out semi-empirical methods, indicating the other methods that they include where applicable.

Austin Model 1, or AM1, is a semi-empirical method for the quantum calculation of molecular electronic structure in computational chemistry.