I found this error in the calculation of two interacting fragments, both with unpaired electrons. So, two radicals interact at a certain distance and the full system is deemed as a singlet, therefore the unpaired electron on each fragment have opposite spins.

Once again, as the year before, I woke to my phone resembling a slot machine from any Vegas casino. #LatinXChem became a Trending Topic on Twitter early from it’s start on september 20th 2021, this year the Twitter poster session was divided into eleven categories (Ana, Bio, Comp, Edu, Eng, Env, Inorg, Mat, Nano, Org, Phys) with Nano and Comp being the ones with the most participants.

The energy of your calculated transition state (TS) is lower than that of the reagents. That’s gotta be an error right? Well, maybe not.

Electronic excitations are calculated vertically according to the Frank—Condon principle, this means that the geometry does not change upon the excitation and we merely calculate the energy required to reach the next electronic state.

The war against COVID-19 has been waged in many fronts. The computational chemistry community has done their share during this pandemic to put forward a cure, a vaccine, or a better understanding of the molecular mechanisms behind the human infection by the SARS-CoV-2 virus.

Molecular Orbitals (MOs) are linear combinations of Atomic Orbitals (AOs), which in turn are linear combinations of other functions called ‘basis functions’. A basis, or more accurately a basis set, is a collection of functions which obey a set of rules (such as being orthogonal to each other and possibly being normalized) with which all AOs are constructed, and although these are centered on each atomic nucleus, the canonical way in which they

Compound 2 represents the first structural example of a 12 e− auride complex, with a pseudohalide/hydride nature in bonding.

I have written about extracting information from excited state calculations but an important consideration when analyzing the results is the proper use of the keyword density . This keyword let’s Gaussian know which density is to be used in calculating some results. An important property to be calculated when dealing with excited states is the change in dipole moment between the ground state and any given state.

Prof. Mario Molina was awarded the Nobel Prize in Chemistry in 1995, the same year I started my chemistry education at the chemistry school from the National Autonomous University of Mexico, UNAM, the same school from where he got his undergraduate diploma. To be a chemistry student in the late nineties in Mexico had Prof.

This is a guest post by our very own Gustavo “ Gus ” Mondragón whose work centers around the study of excited states chemistry of photosynthetic pigments. When you’re calculating excited states (no matter the method you’re using, TD-DFT, CI-S(D), EOM-CCS(D)) the analysis of the orbital contributions to electronic transitions poses a challenge.

The Computational Chemistry Comparison and Benchmark DataBase (CCCBDB) from the National Institute of Standards and Technology (NIST) collects experimental and calculated thermochemistry—related values for 1968 common molecules, constituting a vast source of benchmarks for various kinds of calculations. In particular, scaling factors for vibrational frequencies are very useful when calculating vibrational spectra.