A system can be simulated in vacuum (termed a gas-phase simulation) with no surrounding environment, but this is usually undesirable because it introduces artifacts in the molecular geometry, especially in charged molecules.
Sistem se može simulirati u vakuumu (tzv. simulacija u gasnoj fazi) bez okruženja, mada je to obično nepoželjno pošto uvodi artefakte u molekularnu geometriju, posebno kod naelektrisanih molekula.