Research data for publication: Conformational preferences and benchmarking of computational methods for piperazine-based ligands

This dataset contain computational results for the publication entitled: "Conformational Preferences and Benchmarking of Computational Methods for Piperazine-Based Ligands":(i) conformational sampling results and (ii) benchmark calculations for N-phenylpiperazine (PhP), 2-(piperazin-1-yl)pyrimidine (PyP), and selected derivatives. Conformational sampling identified two dominant orientations (straight, bent) and three ring pucker preferences (chair, boat, twisted-boat). The benchmark includes three protonation states: neutral (Neutral), singly protonated (Positive_1a), and doubly protonated (Positive_2). The benchmark evaluates a set of quantum-chemical methods and basis sets against reference DLPNO-CCSD(T)/CBS(3,4) energies.