{"entity": "researcher", "timestamp": "2026-08-21T22:29:43.383Z", "family": "Costa", "given": "Luciano T", "initials": "LT", "orcid": "0000-0002-9967-4034", "affiliations": ["MolMod-CS - Instituto de Qu\u00edmica, Universidade Federal Fluminense, Niter\u00f3i, RJ CEP 24020-141, Brazil."], "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/researcher/1cc536c679214e99a78d2c1b177b1e7a.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/researcher/1cc536c679214e99a78d2c1b177b1e7a"}}, "publications": [{"entity": "publication", "iuid": "d9d323d768a348ecbcb058ecfbabeb97", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/d9d323d768a348ecbcb058ecfbabeb97.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/d9d323d768a348ecbcb058ecfbabeb97"}}, "title": "The structure of CO2 and CH4 at the interface of a poly(urethane urea) oligomer model from the microscopic point of view.", "authors": [{"family": "Assis Silva", "given": "Flavia Cristina", "initials": "FC", "orcid": "0000-0002-9096-8044", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/ce62a252569b45f0afdfb86546f509af.json"}}, {"family": "da Costa Louren\u00e7o", "given": "Tuanan", "initials": "T", "orcid": "0000-0001-6073-1540", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/5c55c0e4842444479de25ae1fdd3c187.json"}}, {"family": "van der Spoel", "given": "David", "initials": "D", "orcid": "0000-0002-7659-8526", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/a5e69bc348284be9936c3f4ac9c6cb35.json"}}, {"family": "Aparicio", "given": "Santiago", "initials": "S"}, {"family": "Azevedo Dos Reis", "given": "Rodrigo", "initials": "R"}, {"family": "Costa", "given": "Luciano T", "initials": "LT", "orcid": "0000-0002-9967-4034", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/1cc536c679214e99a78d2c1b177b1e7a.json"}}], "type": "journal article", "published": "2021-07-28", "journal": {"title": "J Chem Phys", "issn": "1089-7690", "volume": "155", "issue": "4", "pages": "044704", "issn-l": "0021-9606"}, "abstract": "The world desperately needs new technologies and solutions for gas capture and separation. To make this possible, molecular modeling is applied here to investigate the structural, thermodynamic, and dynamical properties of a model for the poly(urethane urea) (PUU) oligomer model to selectively capture CO2 in the presence of CH4. In this work, we applied a well-known approach to derive atomic partial charges for atoms in a polymer chain based on self-consistent sampling using quantum chemistry and stochastic dynamics. The interactions of the gases with the PUU model were studied in a pure gas based system as well as in a gas mixture. A detailed structure characterization revealed high interaction of CO2 molecules with the hard segments of the PUU. Therefore, the structural and energy properties explain the reasons for the greater CO2 sorption than CH4. We find that the CO2 sorption is higher than the CH4 with a selectivity of 7.5 at 298 K for the gas mixture. We characterized the Gibbs dividing surface for each system, and the CO2 is confined for a long time at the gas-oligomer model interface. The simulated oligomer model showed performance above the 2008 Robeson's upper bound and may be a potential material for CO2/CH4 separation. Further computational and experimental studies are needed to evaluate the material.", "doi": "10.1063/5.0049007", "pmid": "34340392", "labels": [], "xrefs": [], "notes": [], "created": "2026-08-21T11:59:53.599Z", "modified": "2026-08-21T11:59:53.784Z"}, {"entity": "publication", "iuid": "d4d4e2089e34450b9e93ceecc10b0c1e", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/d4d4e2089e34450b9e93ceecc10b0c1e.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/d4d4e2089e34450b9e93ceecc10b0c1e"}}, "title": "A potential for molecular simulation of compounds with linear moieties.", "authors": [{"family": "van der Spoel", "given": "David", "initials": "D", "orcid": "0000-0002-7659-8526", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/a5e69bc348284be9936c3f4ac9c6cb35.json"}}, {"family": "Henschel", "given": "Henning", "initials": "H", "orcid": "0000-0001-7196-661X", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/bc7be8d4d25240d2bb63f020653a50c3.json"}}, {"family": "van Maaren", "given": "Paul J", "initials": "PJ", "orcid": "0000-0002-6068-4585", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/ee278b4160f14181a788614852e0b0b5.json"}}, {"family": "Ghahremanpour", "given": "Mohammad M", "initials": "MM", "orcid": "0000-0002-1129-6041", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/52ee0078c2fc46f1bdacb1b15a9db87f.json"}}, {"family": "Costa", "given": "Luciano T", "initials": "LT", "orcid": "0000-0002-9967-4034", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/1cc536c679214e99a78d2c1b177b1e7a.json"}}], "type": "journal article", "published": "2020-08-28", "journal": {"title": "J Chem Phys", "issn": "1089-7690", "volume": "153", "issue": "8", "pages": "084503", "issn-l": "0021-9606"}, "abstract": "The harmonic angle bending potential is used in many force fields for (bio)molecular simulation. The force associated with this potential is discontinuous at angles close to 180\u00b0, which can lead to numeric instabilities. Angle bending of linear groups, such as alkynes or nitriles, or linear molecules, such as carbon dioxide, can be treated by a simple harmonic potential if we describe the fluctuations as a deviation from a reference position of the central atom, the position of which is determined by the flanking atoms. The force constant for the linear angle potential can be derived analytically from the corresponding force constant in the traditional potential. The new potential is tested on the properties of alkynes, nitriles, and carbon dioxide. We find that the angles of the linear groups remain about 2\u00b0 closer to 180\u00b0 using the new potential. The bond and angle force constants for carbon dioxide were tuned to reproduce the experimentally determined frequencies. An interesting finding was that simulations of liquid carbon dioxide under pressure with the new flexible model were stable only when explicitly modeling the long-range Lennard-Jones (LJ) interactions due to the very long-range nature of the LJ interactions (>1.7 nm). In the other tested liquids, we find that a Lennard-Jones cutoff of 1.1 nm yields similar results as the particle mesh Ewald algorithm for LJ interactions. Algorithmic factors influencing the stability of liquid simulations are discussed as well. Finally, we demonstrate that the linear angle potential can be used in free energy perturbation calculations.", "doi": "10.1063/5.0015184", "pmid": "32872881", "labels": [], "xrefs": [], "notes": [], "created": "2026-08-21T11:59:47.049Z", "modified": "2026-08-21T11:59:47.187Z"}]}