Questions tagged [databases]

Use for questions regarding reference requests for a databases and information about databases

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27 views

Where to find the ChEMBL21 database in CSV format?

I come from an artificial intelligence (AI) background (and not from chemistry). However, my Ph.D. thesis is about Deep Reinforcement Learning for drug design. From one of the most famous papers in ...
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1answer
30 views

Databases for Enthalpy of Solution and Ionic Radii for Ionic Salts

I am looking to investigate the relation between experimental enthalpies of solution and theoretical enthalpies of solution calculated using theoretical equations for the lattice enthalpy and ...
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Recommendation for a searchable database for ligand search in homogenous catalysis?

I am currently trying to preform a database search for phosphite/phosphine ligands that have specific properties (bite-angles, electronic parameters etc.) and don't know which databases there are, ...
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1answer
38 views

g-tensor and hyperfine tensor for nitroxide spin label with 15N

Does anyone know where I can find numerical data for the $g$ tensor and hyperfine tensor for a nitroxide spin label where the nitrogen-14 atom has been replaced by a nitrogen-15 atom? I'm really ...
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Why is the enthalpy of formation of 2,2-dimethylpentane larger than that of 2,2,3-trimethylbutane?

Firstly, it is commonly known and taught that branched alkanes are more stable than linear ones, and so have larger enthalpies of formation. But why is that the case? Are there some steric ...
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Does PubChem have stereocenter location data?

I have spent the last couple of days learning to navigate, find useful information and use the download service on the PubChem website. One of the pieces of information you can find is a stereocenter ...
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1answer
139 views

Source for UV cut-off values of buffers

When I want to check a $\mathrm{p}K_\mathrm{a}$ value I look it up in CRC Handbook. Is there such source for UV cut-off values of various buffers? Usually books in chromatography contain tables with ...
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9 views

Chemistry database for Gibbs energy [duplicate]

Is there good databases for Gibbs energy and other thermal properties? NIST WebBook is okay but easier to browse most common chemical elements like hydrogen, water, oxygen and so on in a table or ...
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19 views

Concentration of organic acids in lichens/rock substrates/soil (particularly oxalic and citric acid)

I am trying to design an experiment testing the efficacy of lichen acids to solubilize and mobilize nutrients from minerals in a lunar regolith simulant. My research so far indicates that oxalic acid ...
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37 views

database for catalytic reaction mechanism

I am looking for a database containing detailed reaction mechanisms for (homogenous) catalytic reactions. Regular organic textbooks or papers generally draw some broad picture of how the mechanism may ...
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80 views

Where can I find literature values for standard molar enthalpies of neutralization?

I'm looking for enthalpy of neutralization literature values for inorganic weak acids. NIST, PubChem, etc. don't list them. Is there somewhere else I should look?
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1answer
54 views

IR absorption chart

I am taking a course in structural determination of organic compounds. Right now, we are giving the IR spectra. I am looking for a table, as detailed as possible, of the absorptions. I hope you can ...
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1answer
245 views

Fundamental vibrational modes for QM9 molecules

QM9 dataset contains about $134000$ small organic molecules with following properties computed using DFT approaches: ...
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29 views

API for molecular classification

We would like to identify an application programming interface (API) which can be fed a SMILES string, PubChem CID, IUPAC name or equivalent, which returns a set of strings corresponding to molecule ...
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93 views

Equilibrium Constants for Diatomic Gases at High Temperatures

I'm new here and I haven't taken chemistry beyond high school, so please forgive the ignorance. I am reading a book about hypersonic aerodynamics, and I am trying to connect some chemistry knowledge ...
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20 views

Any large databases of IR Spectra that you are able to download many spectra in bulk [closed]

I am currently working on a machine learning project, in which I need access to many IR spectra, the more the better, in order to build a classifier that will used some unsupervised learning in order ...
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1answer
59 views

Are there any fluorophores with lifetimes in the micro to milli second range?

I'm looking for a fluorophore with exceptionally long lifetime to use in an oxygen optode (the longer the lifetime the less timing precision needed in the electronics). So far the longest I have ...
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30 views

API or database for verifying chemical reactions [closed]

Is there a database or API(rest calls) for verifying chemical equations? Example, Na + Cl -> NaCl + Loss of energy. So if I want to verify if there is a loss of energy or gain of energy? Is there ...
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2answers
102 views

What are the GDB-13 criteria for "synthetically accessible organic molecules"?

I'm trying to understand the QM datasets (QM7, QM8, QM9), however, in the description of QM7 the data is described as follows: [The] QM7 dataset, which is a subset of GDB-13 (a database of nearly 1 ...
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2answers
253 views

Open resource for spectroscopic raw data

Is anyone aware of reliable resources (ideally public) which allow the user to download the raw spectroscopic data such as infrared spectrum of small organic molecules, or rotational spectrum of HCl/...
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3answers
148 views

Does anyone know a database that shows the effect of electrolyte concentration on the production of hydrogen gas during electrolysis of water?

I'm currently studying in the International Baccalaureate model. This high school model asks their students to do an individual work called the Internal Assessment. One of the subjects I study is ...
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47 views

Unique identifier for chemical substances?

One famous database for chemical substances is PubChem. If one reads the section about other identifiers than the PubChem ID for Ethanol one gets several CAS numbers (potentially deprecated ones as ...
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1answer
122 views

Energy cost of C−N rotation in hydroxamate group

I am looking for a literature reference on the energetic cost of C−N rotation in hydroxamate group such in LC5 in water. I have been googling for a while.
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1answer
123 views

Database for experimental diatomic ionization energies

I am looking for a database, in which the experimental ionization energies (and e.g. heat of formation) of atoms and diatomic molecules are listed as files. If it comes with a Python package, that ...
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3answers
1k views

Are there any datasets containing molecules with more than 38 heavy atoms?

I have been testing a machine learning approach for molecular energy prediction. The current dataset that I have is QM9, which is consist of molecules with up to 9 heavy atoms. I was wondering if ...
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1answer
461 views

What is the meaning of the phase state label (cr,l) appearing in ATcT thermochemical data tables?

I was examining data associated with this post on the heat of solution of ammonium nitrate when I came upon the NIST ATcT data page which lists the heat of formation of $\ce{(NH4)NO3(cr,l)}$. In this ...
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1answer
96 views

What does "reaction rank" in Reaxys stand for?

By exporting some search results from Reaxys, I found "Reaction rank" to be one of the columns in the Excel file. In my file, values descend from 107 to 52 and skip some values in-between too. Does ...
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1answer
101 views

Is there any book where specific heat capacities are given?

I want to find the value of the specific heat capacity of aluminium nitrate nonahydrate, in order to calculate mixing effects in a chemical reaction. I am looking for a source, such as a book or link ...
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2answers
6k views

How can I get xyz coordinates of atoms of a unit cell structure from CIF format files?

I'm trying to run DFT or other 1st principle simulation of Pyrope ($\ce{Mg3Al2Si3O12)}$ and Grossular $\ce{(Ca3Al2[SiO4]3)}$ unit cell structure. So, I'm looking for unit cell xyz periodic box ...
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2answers
425 views

What is a good source for large tables on the properties of water?

I'm currently doing an investigation for school on finding the Clausius-Clapeyron relation/gradient for boiling water and comparing it to the gradients along my line of best fit. It is given by the ...
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115 views

Looking for experimental data for titration curves

I am looking for real, open source and free experimental dataset (not image, scan of table) of acid/base titration curves: pH versus titrant volume for many combination (strong/weak acid/base, ...
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1answer
788 views

Where can I find reliable data for melting points of organic compounds?

I'm interested in the melting/freezing points of organic compounds, but the online literature has data that's all over the map. I can understand that especially for isomers of alkanes, pure samples ...
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1answer
412 views

What is the difference between ΔfH and H-H° in NIST–JANAF tables?

Can someone explain the difference between $Δ_\mathrm{f}H$ and $H-H^\circ$ in NIST–JANAF tables?
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36 views

Online list of water of crystallisation?

I was extremely happy to recently receive a copy of the Nuffield Revised Book of Data but was somewhat disappointed to find that it did not list data on the water of crystallisation for various ...
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163 views

Spectral database in the UV-Vis/NIR and IR regime

I'm searching for a bunch of spectra (some tens), preferably with intense bands in the Vis spectrum, to play around with (calculating chromaticity, etc.). They should range from 250 nm to 2500 nm (UV-...
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353 views

Pseudo 3D skeletal structure style which emphasizes geometry

If one searches and navigates to a wiki page for, say, dichlorodifluoromethane one sees the 2D skeletal structure of the compound as below This representation appears to be of a particular style that ...
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1answer
516 views

Where can I find example MS, IR, NMR spectra for teaching molecular spectroscopy?

I am teaching a course on analytical chemistry, and I would like to give my students MS, IR and NMR spectra to practice with. It would be ideal if they could analyze spectra in a more "realistic" way ...
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1answer
144 views

Help on alternative terpene names and naming schemes

I am a software developer and currently parsing data involving terpene profiles of plant samples. The data in question uses different ways of naming the same terpenes in-between samples and since this ...
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150 views

Experimental bond lengths and binding energies of diatomic molecules

Is it possible to find the experimental values of the bond length and the binding energy of the diatomic molecules $\text H_2$, $\text{Be}_2$, and $\text{Ar}_2$ in one source? I found a lot of ...
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2answers
307 views

How to find chemical market value [closed]

I would like to retrieve pricing information for specific chemicals. Is there a centralized resource for this? Edit: I want to clarify that this type of data is to conduct a techno-economic study. I ...
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1answer
685 views

Molar absorption coefficient of H2SO4(aq) for UV-vis spectrophotometry

I am wondering if there is anything in the literature that can tell me what is the molar absorptivity (i.e. molar extinction coefficient) of aqueous sulfuric acid at a given wavelength (in my case, I ...
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2answers
823 views

What is the correct regular expression for InChI?

When I look for a regular expression for InChI, I succeed on EBI's MIRIAM Registery website: ...
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0answers
93 views

Which organic compounds have the most strongly negative enthalpies of formation?

I've been using the NIST Webbook to list organic compounds and look at their heats of formation (kJ/g, not mol). If I limit myself to three carbons, I still get over 400 results. I can use some ...
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2answers
67 views

Where can I find ranges of isotope abundances?

I'd like to know how much stable isotopes like $\ce{^{13}C}$, $\ce{^2H}$, $\ce{^{17}O}$ and $\ce{^{18}O}$ deviate from their natural abundances in the earth's crust among all possible compounds we may ...
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100 views

Where can I find a downloadable database of basic physical and chemical properties?

The web has many online databases of properties of compounds locked behind search interfaces, but I can't find anything you can actually download. I want a corpus of data that might allow me to, say, ...
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4answers
374 views

What is the best way to convert SMILES strings to file names?

I would like to convert SMILES strings into file names. There are many characters to avoid in file names, i.e. \/:*?"<>| or maybe even ...
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32 views

Deliquescence database

I am looking for a database or printed document providing the RH0 (relative humidity above which deliquescence will occur) for inorganic salts. I've looked everywhere on the internet can find nothing.
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1answer
3k views

Free chemical reactions database

I'm creating a program, which predicts reactions of compound. So, I need a database of chemical reactions. And I need both inorganic and organic reactions. But I can't use Scifinder or Reaxys because ...
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1answer
171 views

Algorithm used by PubChem to determine the 2D layout assignment for Compound entries?

The PubChem database provides 2D structures for entries in its Compounds database: ftp://ftp.ncbi.nlm.nih.gov/pubchem/Compound/ (ftp link to download examples) On the page linked below, under the "...