Environment

• Qiskit version: {'qiskit-terra': '0.24.0', 'qiskit-aer': '0.12.0', 'qiskit-ignis': '0.7.1', 'qiskit-ibmq-provider': '0.20.2', 'qiskit': '0.43.0', 'qiskit-nature': None, 'qiskit-finance': None, 'qiskit-optimization': None, 'qiskit-machine-learning': None}
• Python version: 3.10.6
• Operating system: Linux Mint

What is happening?

Exporting a circuit with small rotation gates through circuit.qasm() results in scientific notation being used. This causes issues when importing the QASM code into another quantum computing platform.

How can we reproduce the issue?

from qiskit import QuantumCircuit
qc = QuantumCircuit(1)
qc.rx(0.00001, 0)
print(qc.qasm())

output:

OPENQASM 2.0;
include "qelib1.inc";
qreg q[1];
creg meas[1];
rx(1e-05) q[0];
barrier q[0];
measure q[0] -> meas[0];

What should happen?

output:

OPENQASM 2.0;
include "qelib1.inc";
qreg q[1];
creg meas[1];
rx(0.00001) q[0];
barrier q[0];
measure q[0] -> meas[0];

Any suggestions?

The conversion from float to string happens in pi_check. The call is pi_check(0.00001, output="qasm", eps=1e-12) and returns '1e-05'.