Welcome to KROME

(better science through chemistry)


KROME is a library-like code to include chemistry and microphysics in a wide range of astrophysical simulations.

Given a chemical network (as plain text) it automatically generates all the routines needed to solve the kinetic of the system, modelled as a system of coupled Ordinary Differential Equations. It provides different options which make it unique and flexible.

Please use the KROME's users mailing list for any problem related to the package or if you have additional comments.

KROME is developed and maintained by Tommaso Grassi, Stefano Bovino, and many others.

KROME is an open-source package, GNU-licensed, and any improvements provided by the users is well accepted.


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updated Set 12, 2022

KROME has been employed in the following papers:
  1. Chemical Evolution During the Formation of Molecular Clouds, Sun et al. (2022)
  2. Unusually High HCO+/CO Ratios in and outside Supernova Remnant W49B , Zhou et al. (2022)
  3. Synthetic observations using POLARIS: an application to simulations of massive prestellar cores , Zamponi et al. (2022)
  4. A survey of high-z galaxies: SERRA simulations, Pallottini et al. (2022)
  5. Molecular Chemistry for Dark Matter. II. Recombination, Molecule Formation, and Halo Mass Function in Atomic Dark Matter, Gurian et al. (2022)
  6. Molecular Chemistry for Dark Matter. III. DarkKROME, Ryan et al. (2022)
  7. High [O III]/[C II] surface brightness ratios trace early starburst galaxies, Vallini et al. (2022)
  8. Chemical analysis of prestellar cores in Ophiuchus yields short timescales and rapid collapse, Bovino et al. (2022)
  9. Establishing the evolutionary timescales of the massive star formation process through chemistry, Sabatini et al. (2022)
  10. On the low ortho-to-para H2 ratio in star-forming filaments, Lupi et al. (2022)
  11. Gravitational fragmentation of extremely metal-poor circumstellar discs , Shima et al. (2022)
  12. High-redshift quasars and their host galaxies - II. Multiphase gas and stellar kinematics, Lupi et al. (2022)
  13. Modelling H2 and its effects on star formation using a joint implementation of GADGET-3 and KROME, Sillero et al. (2021)
  14. Adaptive numerical simulations with Trixi.jl: A case study of Julia for scientific computing, Ranocha et al. (2021)
  15. Dwarf Satellites of High-z Lyman Break Galaxies: A Free Lunch for JWST, Gelli et al. (2021)
  16. Dust temperature in ALMA [C II]-detected high-z galaxies , Sommavigo et al. (2021)
  17. Dynamical properties of Molecular Cloud Complexes at the Epoch of Reionization, Leung et al. (2021)
  18. Deuterium Chemodynamics of Massive Pre-Stellar Cores, Hsu et al. (2021)
  19. Dense and warm neutral gas in BR1202-0725 at z = 4.7 as traced by the [OI] 145μm line, Lee et al. (2021)
  20. Magnetic field amplification in accretion discs around the first stars:implications for the primordial IMF, Sharda et al. (2021)
  21. UV absorption lines and their potential for tracing the Lymancontinuum escape fraction, Mauerhofer et al. (2020)
  22. Early galaxy growth: mergers or gravitational instability, Zanella et al. (2020)
  23. Velocity dispersion in the interstellar medium of early galaxies, Kohandel et al. (2020)
  24. The stellar populations of high-redshift dwarf galaxies, Gelli et al. (2020)
  25. Shaping the structure of a GMC with radiation and winds , Decataldo et al. (2020)
  26. Synthetic observations of deuterated molecules in massive prestellarcores, Zamponi et al. (2020)
  27. Constraining galactic structures of mirror dark matter, Roux et al. (2020)
  28. The importance of magnetic fields for the initial massfunction of the first stars, Sharda et al. (2020)
  29. Predicting FIR lines from simulated galaxies , Lupi et al. (2020)
  30. Impact of an Active Sgr A* on the Synthesis of Water and OrganicMolecules Throughout the Milky Way, Liu et al. (2020)
  31. Global Hydromagnetic Simulations of Protoplanetary Disks with Stellar Irradiation and Simplified Thermochemistry, Gressel et al. (2020)
  32. Dynamical Properties of Molecular-forming Gas Clumps in Galaxies at the Epoch of Reionization, Leung et al. (2020)
  33. Globular Cluster Formation from Colliding Substructure, Madau et al. (2020)
  34. The [C II]-SFR correlation in dwarf galaxies across cosmic time , Lupi et al. (2020)
  35. Constraining galactic structures of mirror dark matter , Roux et al. (2020)
  36. The 3D Structure of CO Depletion in High-mass Prestellar Regions , Bovino et al. (2019)
  37. UV regulated star formation in high-redshift galaxies , Latif et al. (2019)
  38. The role of the H2 adiabatic index in the formation of the first stars , Sharda et al. (2019)
  39. Photoevaporation of Jeans-unstable molecular clumps, Decataldo et al. (2019)
  40. Synthetic molecular line observations of the first hydrostatic core from chemical calculations, Young et al. (2019)
  41. Kinematics of z ≥ 6 galaxies from [C II] line emission , Kohandel et al. (2019)
  42. Planet-forming material in a protoplanetary disc: the interplay between chemical evolution and pebble drift, Booth et al. (2019)
  43. Impact of radiation backgrounds on the formation of massive black holes , Díaz et al. (2019)
  44. Ly α emission from galaxies in the Epoch of Reionization, Behrens et al. (2019)
  45. Deep into the structure of the first galaxies: SERRA views, Pallottini et al. (2019)
  46. Black hole formation in the context of dissipative dark matter, Latif et al. (2019)
  47. The role of gas fragmentation during the formation of supermassive black holes, Suazo et al. (2019)
  48. Intermittent fragmentation and statistical variations during gas collapse in magnetised atomic cooling haloes, Grete et al. (2019)
  49. High-redshift quasars and their host galaxies I: kinematical and dynamical properties and their tracers, Lupi et al. (2019)
  50. H2 chemistry in galaxy simulations: an improved supernova feedback model, Lupi et al. (2019)
  51. Developing a self-consistent AGB wind model: I. Chemical, thermal, and dynamical coupling, Boulangier et al. (2018)
  52. Lampray: Multi-group long characteristics ray tracing for adaptive mesh radiation hydrodynamics, Frostholm et al. (2018)
  53. The formation of protostellar binaries in primordial minihaloes, Riaz et al. (2018)
  54. H2 chemistry in galaxy simulations: an improved supernova feedback model, Lupi et al. (2018)
  55. The natural emergence of the correlation between H2 and star formation rate surface densities in galaxy simulations, Lupi et al. (2017)
  56. The effect of non-equilibrium metal cooling on the interstellar medium, Capelo et al. (2017)
  57. Fast deuterium fractionation in magnetized and turbulent filaments, Körtgen et al. (2017)
  58. H2 ortho-to-para conversion on grains: A route to fast deuterium fractionation in dense cloud cores?, Bovino et al. (2017)
  59. The impact of chemistry on the structure of high-z galaxies, Pallottini et al. (2017)
  60. Massive Black Holes from Dissipative Dark Matter, D'Amico et al. (2017)
  61. Deuterium fractionation and H2D+ evolution in turbulent and magnetized cloud cores, Körtgen et al. (2017)
  62. Modelling the chemistry of star forming filaments - II. Testing filament characteristics with synthetic observations, Seifried et al. (2017)
  63. Modeling the role of electron attachment rates on column density ratios for CnH-/CnH (n=4,6,8) in dense molecular clouds, Gianturco et al. (2016)
  64. A detailed framework to incorporate dust in hydrodynamical simulations, Grassi et al. (2016)
  65. The formation of the primitive star SDSS J102915+172927: effect of the dust mass and the grain-size distribution, Bovino et al. (2016)
  66. A chemical model for the interstellar medium in galaxies, Bovino et al. (2016)
  67. Connecting the evolution of thermally pulsing asymptotic giant branch stars to the chemistry in their circumstellar envelopes, Marigo et al. (2015)
  68. Modelling the chemistry of star forming filaments, Seifried et al. (2015)
  69. Witnessing the birth of a supermassive protostar, Latif et al. (2015)
  70. Impact of dust cooling on direct collapse black hole formation, Latif et al. (2015)
  71. Seeding High Redshift QSOs by Collisional Runaway in Primordial Star Clusters, Katz et al. (2015)
  72. Assessing inflow rates in atomic cooling halos: implications for direct collapse black holes, Latif et al. (2015)
  73. The origin of spin in galaxies: clues from simulations of atomic cooling haloes, Prieto et al. (2015)
  74. The formation of supermassive black holes in rapidly rotating disks, Latif et al. (2015)
  75. How realistic UV spectra and X-rays suppress the abundance of direct collapse black holes, Latif et al. (2015)
  76. Disc fragmentation and the formation of Population III stars, Latif et al. (2015)
  77. The chemical evolution of self-gravitating primordial disks, Schleicher et al. (2015)
  78. KROME - a package to embed chemistry in astrophysical simulations, Grassi et al. (2014)
  79. Effects of turbulence and rotation on protostar formation as a precursor to seed black holes, Van Borm et al. (2014)
  80. Dark-matter halo mergers as a fertile environment for low-mass Population III star formation, Bovino et al. (2014)
  81. Formation of carbon-enhanced metal-poor stars in the presence of far ultraviolet radiation, Bovino et al. (2014)
  82. The formation of massive primordial stars in the presence of moderate UV backgrounds, Latif et al. (2014)
  83. A UV flux constraint on the formation of direct collapse black holes, Latif et al. (2014)
  84. Primordial star formation: relative impact of H2 three-body rates and initial conditions, Bovino et al. (2014)
  85. Reducing Si population in the ISM by charge exchange collisions with He+: a quantum modelling of the process, Satta et al. (2013)
  86. Impact of an accurate modelling of primordial chemistry in high-resolution studies, Bovino et al. (2013)
  87. CH+ depletion by atomic hydrogen: accuracy of new rates in photo-dominated and self-shielded environments, Bovino et al. (2013)
  88. Exploring planetary biomarkers: a new physical method coupled with new computational tool, Simoncini et al. (2013)
Complete list of citations from ADS (150+).


KROME receives AG Software Award

Dr Tommaso Grassi from the Max Planck Institute for Extraterrestrial Physics, Garching, and Dr Stefano Bovino from the Department of Astronomy, Universidad de Concepción, Chile, jointly receive the Astrophysical Software Award for the development of the astrochemistry package KROME. KROME is an open-source code that was developed to include chemistry and thermal processes in numerical hydrodynamical simulations to properly describe the thermal evolution of gas. It is a key tool to study, among the others, star-forming regions, galaxy evolution, black hole formation, complex chemical pathways, as well as to compare simulations with observational data of atomic or molecular lines. KROME can model any chemical network for which the reaction rates are known and includes modules to incorporate dust physics. The development of KROME has expanded the possibilities for modelling thermochemistry in astrophysical simulations and has contributed to significant advances in astrophysical knowledge and to the education of students and postdocs in astrochemistry.

Here the various press releases:

AG society | MPE | UdeC

Astrophysicists model the formation of the oldest-known star in our galaxy

The astrochemistry package KROME has been employed by scientists at the Universities of Göttingen and Copenhagen to model the formation of the oldest-known star in the Milky Way, SMSS J031300.36-670839.3, with the cosmological hydrodynamics code Enzo. The simulations included the observed stellar abundance patterns for the metals, as well as the dynamics of gas and dark matter. The star modeled is part of the class of the carbon-enhanced metal poor stars, with tiny abundances of metals but relatively enhanced fractions of carbons. The simulations show that efficient cooling is still possible under these conditions, and that the gas reaches the temperature of the cosmic microwave background during the collapse. As a result, efficient fragmentation may occur, and the formation of low-mass stars becomes possible.

The attached illustration shows projections of the gas density, temperature and the fraction of ionized carbon in the central region where the star forms, in simulations with different abundances of the heavy elements, from 0.01 to 0.0001 times the solar value. The results show that a strong transition occurs for a carbon abundance of 0.01 times the solar value, providing a pathway for the formation of low-mass stars.

phys.org | SNM | UniGoe | INAF (Italian) | ApJL | arXiv

About Us

KROME is developed by several astrophysicists and chemists from different host institutions

Main developer:    Tommaso GrassiUSM/LMU, München(tgrassi AT mpe.mpg.de)
Co-developer and Enzo interface: Stefano BovinoDepartamento de Astronomía, Universidad de Concepción (stefanobovino AT astro-udec.cl)
RAMSES interface:    Joaquìn PrietoICC, University of Barcelona (IEEC-UB) (joaquin.prieto.brito AT gmail.com)
FLASH interface:    Daniel SeifriedUniversity of Köln (seifried AT ph1.uni-koeln.de)
Thermochemistry:   Eugenio SimonciniINAF - Arcetri, Florence, Italy (eugenio.simoncini AT gmail.com)
C and Python interface:   Jon RamseyUniversity of Virginia (Dept. of Astronomy) (jpramsey AT virginia.edu)
Supervisor / RAMSES:   Troels HaugbølleSTARPLAN, Natural History Museum of Denmark / NBI(haugboel AT nbi.dk)
Supervisor:   Dominik SchleicherDepartamento de Astronomía, Universidad de Concepción (dschleicher AT astro-udec.cl)
Supervisor:   Francesco GianturcoIntitut fuer Ionenphysik und Angewandte Physik, Innsbruck (francesco.gianturco AT uibk.ac.at)

Additional contributors are J.Boulangier, T.Frostholm, D.Galli, A.Lupi, and E.Tognelli.