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Questions tagged [databases]

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

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Searching for a phase transition dataset for substances

Disclaimer: I'm not a chemist, just a curious engineer. As per the title, I'm searching for a dataset (or relevant Python library) with phase transition information for different substances. Eg: water,...
sebzuddas's user avatar
1 vote
0 answers
54 views

Theoretic (QED) Atomic Ionization Energies Database?

The 2019 paper "QED tests with highly-charged ions" contains a survey of QED-calculated atomic ionization energies. I can manually copy the values of interest therein, but it seem that ...
James Bowery's user avatar
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Automatically extracting SMILES of sub-group of larger SMILES structure?

Is there any software tool that can automatically extract SMILES of fatty acid legs of phospholipids if the SMILES of the parent lipid is given? Or any tool that can do it in InChI ? Any advice will ...
user1776194's user avatar
2 votes
0 answers
211 views

Activation energy of the reaction between magnesium carbonate and hydrochloric acid

I've been working on a project that uses some abnormal methods to calculate the activation energy using only one trial of an exothermic reaction. However now that I've completed the lab, I want to ...
Redmac's user avatar
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1 vote
1 answer
258 views

QM9 atomization energies

I am doing experiments with the QM9 dataset from http://quantum-machine.org/datasets/ and began with some simple checks on results from the literature. Consistent with what the authors of the paper ...
Arnold Neumaier's user avatar
1 vote
0 answers
118 views

API to get GHS info given substance / CAS #

Is there an API that can provide the GHS info for a given substance / CAS #? If not, which website is the most extensive to get GHS info for a given substance / CAS # in human-readable format?
Dan P.'s user avatar
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1 vote
1 answer
1k views

accessing the ZINC15 and ZINC20 databases

I'm trying to access the ZINC15 and ZINC20 databases but I've been at it the whole morning and I can not figure out how to do it. I am not that experienced with programming so maybe there's something ...
apvn's user avatar
  • 75
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0 answers
91 views

Database of atomic crystal structure data or images of rocks and minerals?

I am looking for crystal structure images so I can redraw them in a nice form. However, I don't seem to find much searching Google. Perhaps this is a slightly better example (searching for Quartz ...
Lance's user avatar
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1 vote
0 answers
1k views

Full list of CAS numbers?

I'm trying to find a full list of CAS Registry Numbers, but it looks like it's not in open access. Is it a proprietary database that can't be downloaded easily?
Stefan Smirnov's user avatar
0 votes
0 answers
54 views

Data for Madelung Constants

Where can I find data for the Madelung constants for various ionic compounds? Specifically, I am looking at silicon tetrachloride, yttrium (III) chloride, zirconium (IV) oxynitrate hydrate, niobium (V)...
Zachary Ireland's user avatar
4 votes
0 answers
93 views

Mapping of half-life decay for all elements/isotopes

Is there an open resource that helps illustrate all paths of decay for all isotopes (e.g. $\ce{^{99}Mo}$ decaying to $\ce{^\mathrm{99m}Tc})?$ I know the result state/transition map would be massive, ...
VenomFangs's user avatar
-4 votes
1 answer
272 views

Where can i find accurate bond angles?

I am trying to find places where I can have accurate bond angles of certain molecules such as $\ce{F2Se}$, $\ce{Cl2S}$, or even $\ce{S2Se}. I have looked everywhere and have found only 3 sources that ...
Adrien Bonansea's user avatar
2 votes
1 answer
110 views

Unique notation to search for compounds in PubChem and in Chembl

I am not a chemist, I come from a computer science background. I am working on a project related to computer-aided drug design. I have a list of chemical compounds in their SMILES notation, to which I ...
mac179's user avatar
  • 319
3 votes
1 answer
238 views

What Chemical Database Extensions for Structure and Similarity Search are there?

I am looking for extensions/add-ons for relational databases (RDBMS) that enable storing and handling chemical structures including the possibility for substructure searches and similarity search. I ...
buddemat's user avatar
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1 vote
0 answers
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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 ...
mac179's user avatar
  • 319
0 votes
1 answer
1k 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 ...
planckton's user avatar
2 votes
1 answer
72 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 ...
Ben's user avatar
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2 votes
0 answers
243 views

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 ...
Vorld's user avatar
  • 37
5 votes
0 answers
68 views

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 ...
Dragonoverlord3000's user avatar
5 votes
1 answer
2k 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 ...
JohnRiley's user avatar
3 votes
0 answers
48 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 ...
Greg's user avatar
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0 votes
0 answers
306 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?
KJB's user avatar
  • 11
0 votes
1 answer
122 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 ...
Carlos's user avatar
  • 607
4 votes
1 answer
296 views

Fundamental vibrational modes for QM9 molecules

QM9 dataset contains about $134000$ small organic molecules with following properties computed using DFT approaches: ...
Blade's user avatar
  • 1,503
1 vote
0 answers
43 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 ...
John Chris's user avatar
2 votes
0 answers
110 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 ...
Publius's user avatar
  • 31
2 votes
0 answers
38 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 ...
finlay morrison's user avatar
1 vote
1 answer
96 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 ...
norlesh's user avatar
  • 537
1 vote
0 answers
177 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 ...
Yateen Gupta's user avatar
2 votes
2 answers
153 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 ...
Darien Schettler's user avatar
7 votes
2 answers
894 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/...
AChem's user avatar
  • 40.9k
2 votes
3 answers
260 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 ...
Alejandro Rodriguez Rebollo's user avatar
3 votes
0 answers
158 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 ...
thinwybk's user avatar
  • 219
3 votes
1 answer
126 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.
BND's user avatar
  • 392
0 votes
1 answer
189 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 ...
Uwe.Schneider's user avatar
16 votes
3 answers
2k 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 ...
Blade's user avatar
  • 1,503
1 vote
1 answer
2k 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 ...
Buck Thorn's user avatar
  • 22.1k
9 votes
1 answer
149 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 ...
odnerpmocon's user avatar
2 votes
1 answer
171 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 ...
rohit shanbhag's user avatar
8 votes
2 answers
12k 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 ...
exsonic01's user avatar
  • 227
6 votes
2 answers
442 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 ...
John Miller's user avatar
0 votes
0 answers
204 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, ...
jlandercy's user avatar
  • 928
2 votes
1 answer
2k 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 ...
M.Hutson's user avatar
  • 193
1 vote
1 answer
973 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?
ben's user avatar
  • 19
1 vote
0 answers
40 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 ...
Isky Mathews's user avatar
2 votes
0 answers
192 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-...
chimera's user avatar
  • 21
5 votes
0 answers
423 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 ...
John Chris's user avatar
3 votes
1 answer
2k 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 ...
Martin's user avatar
  • 721
2 votes
1 answer
158 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 ...
Max Fuxjäger's user avatar
0 votes
0 answers
189 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 ...
thyme's user avatar
  • 319