Questions tagged [chemistry]
For questions regarding (or related to) applications of quantum information theory in chemistry or applications of chemistry in quantum computing.
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Quantum Phase Estimation for Chemical Hamiltonian
I am working on implementing QPE for calculating the ground state energy of a small molecule like H2 or HeH+. I've written some code that is getting results within about 10% accuracy, but I'm not ...
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2
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Feasibility of Applying QAOA to Quantum Chemistry Calculations
Is it possible to apply QAOA (or quantum alternating operator ansatz) to quantum chemistry calculations for NISQ devices? If not, why? If it is possible, why is it not commonly seen?
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What problems in chemistry or materials science could be solved with 100 fault-tolerant qubits?
Background
IBM, Infleqtion, QuEra, and other quantum hardware companies have announced roadmaps where they expect to have 100 or more fault-tolerant qubits by the end of the decade. It seems ...
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Modeling a chemical reaction when there is a catalyst
I'd like to construct potential energy surfaces (PES) for chemical reactions with and without the presence of a catalyst. Something like this
The closest paper that is https://arxiv.org/pdf/2007....
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Approximate decomposition of general $n$-qubit unitary to universal gate set
The Solovay-Kitaev algorithm claims that any $n$-qubit unitary gate can be decomposed to $O(\log^c(1/\epsilon))$ gates in any given universal gate set, e.g. Clifford+T.
However, the number of qubits $...
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Pennylane Spectral gap for Molecules
Pennylane's dataset has a lot of systems, including Quantum Chemistry molecules. Can I extract the spectral gap of the molecule from the dataset (assuming it contains the number). In the case that ...
- 391
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Solving the one-electron integral manually in second quantized form
When I am looking into the Hartree-Fock solution to the many bodies electronic system, I came across the one electron integral, which is defined as:
$$h_{pq}=\int{\psi_p^\ast\left(r\right)\left(-\frac{...
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How to define an energy function, for predicting protein structure in quantum computing? [closed]
Let q denote a particular configuration of the protein in a grid, written in the form
where $x_i$ and $y_i$ are the $x$ and $y$ coordinate of the $i$th amino acid. For this configuration, how to ...
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Updating qiskit.chemistry.core.Hamiltonian to qiskit-nature Framework
I recently saw a piece of code that computes molecular bond energy with respect to bond length. I am trying to update the code to the newer qiskit framework (I'm running qiskit 0.45.1 and ...
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Understanding the Role of Qiskit's VQE Code in Light of Pre-calculated Zero-Point Vibrational Energy in Gaussian Files
In the context of quantum computational chemistry, the Qiskit VQE (Variational Quantum Eigensolver) code is often used to calculate the vibrational energies of molecules, including the zero-point ...
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Advantage of quantum computers over classical computers in fully modeling interactions between atoms?
I'm trying to better understand the advantage quantum computers offer in terms of their ability to more accurately model chemical reactions. As a way to come to a deeper understanding, my question is:
...
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Help me to find error in finding Cost Function for SSVQE algorithm [closed]
Q: Build SSVQE's cost function using the following observable: $$O=2II−2XX+3YY−3ZZ\,.$$
This cost function should take in parameters as input. Use the included variational form, with reference states $...
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Difference between Qiskit and Openfermion two body integrals
I am struggling with understanding the differences between OpenFermion and Qiskit libraries when it comes to Molecular Data, two body integrals.
For example, I am working with the following ...
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Subespace Search Variational Quantum Eigensolver (SSVQE) with contraints
I am trying to reproduce this paper: https://arxiv.org/pdf/2211.02302.pdf. However, I am having problems in getting the singlet first excited state (S1). The authors in the paper, they use the SSVQE ...
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Can someone explain how Qiskit defines the electronic dipole moments?
The Qiskit API defines the electronic dipole moment as
$$
\hat{d} = \sum_{p,q} d_{pq}^x a_p^\dagger a_q ,
$$
where
$d_{pq}^x,d_{pq}^y,$ and $d_{pq}^z$ are the Cartesian components of the vector
$$
\...
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