Use a cheminformatics toolkit such as Open Babel to convert among SMILES, MOL, and SDF. For a typical SMILES file to SDF conversion, run obabel input.smi -O output.sdf. Conversion changes the file representation; it does not necessarily generate coordinates or preserve every data field, so check the output in the software that will use it.
What changes when you convert these formats?
SMILES is a line notation: it represents molecular connectivity and can encode details such as chirality. Open Babel implements the OpenSMILES specification and documents its SMILES reader and writer (Open Babel SMILES format; OpenSMILES specification).
As an Amazon Associate I earn from qualifying purchases.
MOL is an MDL structure-file format. Open Babel documents support for V2000 and V3000 MOL files. SDF, or SDfile, stores molecular records and can include associated data fields; MOL and SDF are related MDL table-based formats (Open Babel MDL MOL format; Daylight Web Services Manual).
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
These formats do not carry exactly the same kinds of information. A SMILES string does not itself provide a coordinate drawing, while SDF can hold coordinates and per-record properties. Decide which details your destination needs before converting.
#1 Best Overall
- FOR BASIC TEACHING TO ADVANCED SCIENCE: 444 pieces molecular model kit, including 136 atoms, 158 bonds and 150 parts for Carbon-60(Fullerene), provides to students from Grade 7 to Graduate level.
- TWO CHEMICAL STRUCTURE MODELS: The ball-and-stick models use spheres to represent atoms and sticks to represent chemical bonds. In the space-filling model, the spheres are drawn to scale and are next to one another as atoms are in real molecules.
- CHEMISTRY EDUCATIONAL MOLECULE MODEL IN 3D: It can display chemical structure, molecular bond, and bond angle in all directions. Demonstrate fundamental molecular geometry, chemical molecular structure, stereochemistry with 3D modeling studies.
- EASY TO LEARN: The universal standard adopted for each atom's color makes it easier for you to use and learn. Atoms and chemical bonds combine tightly and firmly and can be easily disassembled by disconnecting tools.
- If you’re not in love with it for whatever reason, we’ll give you a full replacement or refund—no questions asked. If you have any doubt, please tell us. With nothing to worry about, or even to share with your friends, try it now.
Convert files with Open Babel
Open Babel’s obabel command reads and writes molecular formats. Its documented pattern is to name the input and set the output with -O (Open Babel command-line guide).
SMILES file to SDF
obabel input.smi -O output.sdfThis reads structures from input.smi and writes them to output.sdf. A multi-line SMILES file should contain one structure per line, with any identifier or name placed where the consuming tool expects it.
Rank #2
- ADVANCED LEARNING SCIENCE EDUCATION KIT --- Perfect chemistry model kit for modeling simple and small to more advanced and complex chemical structures for schools and college level, students of all ages, researchers and enthusiasts. Fun and interactive early learning molecular set for kids of all years and for use in the classroom.
- HIGH QUALITY --- Made from high quality durable materials designed for easy construction and perfect fit. These Molecular Model Kit pieces are color coded to national standards for easy ID. Organic Chemistry Model Kit includes box for easy storage and transport with your other textbooks, notes, and books. Excellent for the classroom.
- POWERFUL FUNCTIONS --- This Molecular Model Kit has a total of 136 pieces including short link remover tool. Super easy to build models for organic and inorganic chemistry, This model contains C, H, O, N, S and a variety of single and double bonds, Can be put high school, university chemistry in most of the organic or inorganic molecular structure model for the study of experimental operation.
- QUICK AND EASY ASSEMBLY OF COMPLEX STRUCTURES --- Atoms and bonds that are perfectly suited to being connected and disconnected easily without making your fingers hurt. We've also included a link remover to make the task of easy.
- CONVENIENT STORAGE --- The pieces come in a slim plastic box for convenient storage. See the pictures on this listing for a full understanding of what's inside
SDF to SMILES file
obabel input.sdf -O output.smiThis writes SMILES representations of the input records. If identifiers or SDF property fields matter, plan to retain or export them separately: conversion to SMILES does not make those fields part of the molecular line notation, and field retention can depend on the conversion path.
Specify formats when extensions are missing or misleading
obabel -ismi input.data -osdf -O output.dataThe -i and -o switches explicitly identify input and output formats. Use them when a filename has no useful suffix or its extension does not match the file contents.
Rank #3
- Visualize Molecular: The molecular model kit simplifies complex chemistry concepts into tangible 3D structures improve learning efficiency, suitable for students from Grade 7 to Graduate level.
- 444 Pcs Complete Set: The atom model kit includes with 136 atoms,158 bonds, and 150 fullerene model parts, explore most the molecules structures from simple compounds to complex polymers.
- Effortless Assembly: Embedded component design ensures easy to construct Ball-and-stick and Space-filling models that maximizes focus on exploration without complex assembly.
- Durable & Portable: Built to last, the chemistry set is crafted from high-quality materials. Plus, its portable Snap-Lock design allows you to take your experiments learning anywhere, between the home, classroom and lab.
- Essential Study Tool: Whether you're studying organic chemistry, biochemistry, or molecular biology, molecule building kit is an perfect learning tool for you deeper comprehension of molecular science.
Add coordinates only if the workflow needs them
Open Babel does not generate coordinates unless asked. A conversion from SMILES can therefore produce an SDF record without a 2D or 3D drawing. For generated 3D coordinates, use the documented --gen3d option:
obabel input.smi -O output.sdf --gen3dOpen Babel also documents --gen2d for 2D coordinate generation. Coordinate generation is a modeling step, not an automatic consequence of changing formats. Use it only when the downstream program needs coordinates, and check that the resulting geometry is suitable for the intended use.
Rank #4
- UNLOCK YOUR CHEMISTRY POTENTIAL: Our comprehensive molecular model kit includes 238 pieces, featuring 84 atoms, 153 bonds and a remover tool. Suitable for chemistry learners from beginners to advanced levels. Manufacturer recommended age: 15 years and up
- ORGANIZED STORAGE AND EASY LOCATING: Experience hassle-free organization with our storage box, complete with divided compartments and labeled sections. Say goodbye to clutter and quickly find the components you need
- EXTRA LEARNING MATERIALS FOR EXCELLENCE: Enhance your studies with our bonus 6-page learning guide and stencils. From grade 9 to college, from organic to inorganic, finish and master your assignments faster and create numerous molecular structures with ease
- IMMERSIVE 3D VISUAL LEARNING: Explore chemistry in a captivating way with our 3D visual learning approach. The universal color-coded Atomic Balls provide a better understanding of molecular structure, boosting your chemistry knowledge. It's also a perfect gift for someone who are going to learn those complex molecule
- EASY-TO-USE DESIGN: Crafted from smooth, burr-free plastic, our molecular science kit ensures easy assembly. With the included remover tool, disassembling is a breeze
Check stereochemistry, MOL version, and record data
Stereochemistry
Open Babel documents support for tetrahedral and cis/trans stereochemistry in zero-dimensional MOL files as an extension, along with options that affect whether such stereochemistry is read or written. Its MOL documentation also distinguishes handling for 2D and 3D coordinate records (Open Babel MDL MOL format). Preserve isomeric detail deliberately and verify the result in the destination application; format support alone does not guarantee that every application interprets the representation identically.
V2000 and V3000
Open Babel documents reading and writing both MOL V2000 and V3000. Confirm which version your destination accepts, especially if the structure or workflow depends on capabilities not supported by an older format or program.
Best Value
- Visualize Molecular: The molecular model kit simplifies complex chemistry concepts into tangible 3D structures improve learning efficiency, suitable for students from Grade 7 to Graduate level.
- 240 Pcs Complete Set: The atom model kit includes with 86 atoms and 154 bonds, explore most the molecules structures from simple compounds to complex polymers.
- Effortless Assembly: Embedded component design ensures easy to construct Ball-and-stick and Space-filling models that maximizes focus on exploration without complex assembly.
- Durable & Portable: Built to last, the chemistry set is crafted from high-quality materials. Plus, its portable design allows you to take your experiments learning anywhere, between the home, classroom and lab.
- Essential Study Tool: Whether you're studying organic chemistry, biochemistry, or molecular biology, molecule building kit is an perfect learning tool for you deeper comprehension of molecular science.
SDF properties and identifiers
SDF records can include data in addition to molecular structure. When converting to SMILES, decide how names, identifiers, and SD tags will be retained or exported. Do not assume every toolkit-specific property or vendor extension survives a conversion.
Validate the converted output
For representative records, open the output with the software that will consume it and check:
- Each structure parses and the file has the expected number of records.
- Atom and bond connectivity, including stereochemistry, matches the intended structure.
- Coordinates are present if the workflow requires 2D or 3D geometry.
- Identifiers and required SDF data fields are available after conversion.
- The MOL version and other format details are compatible with the destination program.
Hydrogen-handling options can add or remove atoms, and therefore change the represented structure. Open Babel documents such options, but they should be used only when that change is intended. Check the installed Open Babel version’s supported formats and options before relying on a command in a production workflow; behavior should not be assumed identical across all toolkit versions.
Free tools Windows power users keep installed
One-click scans. No signup required.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
