MC-PDFT can calculate singlet-triplet splittings of organic diradicals

Samuel J. Stoneburner, Donald G. Truhlar, Laura Gagliardi

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


The singlet-triplet splittings of a set of diradical organic molecules are calculated using multiconfiguration pair-density functional theory (MC-PDFT), and the results are compared with those obtained by Kohn-Sham density functional theory (KS-DFT) and complete active space second-order perturbation theory (CASPT2) calculations. We found that MC-PDFT, even with small and systematically defined active spaces, is competitive in accuracy with CASPT2, and it yields results with greater accuracy and precision than Kohn-Sham DFT with the parent functional. MC-PDFT also avoids the challenges associated with spin contamination in KS-DFT. It is also shown that MC-PDFT is much less computationally expensive than CASPT2 when applied to larger active spaces, and this illustrates the promise of this method for larger diradical organic systems.

Original languageEnglish (US)
Article number064108
JournalJournal of Chemical Physics
Issue number6
StatePublished - Feb 14 2018

Bibliographical note

Publisher Copyright:
© 2018 Author(s).


Dive into the research topics of 'MC-PDFT can calculate singlet-triplet splittings of organic diradicals'. Together they form a unique fingerprint.

Cite this